U.S. patent application number 14/388271 was filed with the patent office on 2015-02-19 for electrolysis device and temperature-adjusting water-supplying apparatus provided with same.
This patent application is currently assigned to DAIKIN INDUSTRIES, LTD.. The applicant listed for this patent is DAIKIN INDUSTRIES, LTD.. Invention is credited to You Agata, Isao Fujinami, Yutaka Shibata, Kaori Yoshida.
Application Number | 20150047973 14/388271 |
Document ID | / |
Family ID | 49259039 |
Filed Date | 2015-02-19 |
United States Patent
Application |
20150047973 |
Kind Code |
A1 |
Yoshida; Kaori ; et
al. |
February 19, 2015 |
ELECTROLYSIS DEVICE AND TEMPERATURE-ADJUSTING WATER-SUPPLYING
APPARATUS PROVIDED WITH SAME
Abstract
An electrolysis device removes a scale component contained in
water that is fed to a water heat exchanger. The electrolysis
device has a container having a water inlet port and a water outlet
port; a plurality of electrodes provided inside the container; and
agitation means for agitating water, between adjacent electrodes,
that flows from the water inlet port towards the water outlet
port.
Inventors: |
Yoshida; Kaori; (Sakai-shi,
JP) ; Shibata; Yutaka; (Sakai-shi, JP) ;
Agata; You; (Sakai-shi, JP) ; Fujinami; Isao;
(Sakai-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
DAIKIN INDUSTRIES, LTD. |
Osaka-shi, Osaka |
|
JP |
|
|
Assignee: |
DAIKIN INDUSTRIES, LTD.
Osaka-shi, Osaka
JP
|
Family ID: |
49259039 |
Appl. No.: |
14/388271 |
Filed: |
March 27, 2013 |
PCT Filed: |
March 27, 2013 |
PCT NO: |
PCT/JP2013/002103 |
371 Date: |
September 26, 2014 |
Current U.S.
Class: |
204/239 |
Current CPC
Class: |
C02F 2103/023 20130101;
F24D 2200/123 20130101; C02F 1/46104 20130101; C02F 2209/006
20130101; C02F 2301/024 20130101; C02F 2201/4617 20130101; F24D
19/0092 20130101; C02F 1/4602 20130101; F24D 17/02 20130101; C02F
2201/46145 20130101; C02F 2001/46138 20130101; C02F 2001/46157
20130101; C02F 2201/4611 20130101; C02F 2001/46152 20130101; C02F
2301/028 20130101; C02F 2301/046 20130101; C02F 2201/4613 20130101;
C02F 2301/043 20130101 |
Class at
Publication: |
204/239 |
International
Class: |
C02F 1/461 20060101
C02F001/461 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 28, 2012 |
JP |
2012-073618 |
Mar 30, 2012 |
JP |
2012-079547 |
Dec 3, 2012 |
JP |
2012-264147 |
Claims
1. An electrolysis device for removing a scale component contained
in water that is fed to a water heat exchanger, comprising: a
container having a water inlet port and a water outlet port; a
plurality of electrodes provided inside the container; and an
agitation part configured to agitate water that flows between
adjacent electrodes, between the water inlet port and the water
outlet port.
2. The electrolysis device according to claim 1, wherein the
agitation part includes a component that is separate from the
electrodes.
3. The electrolysis device according to claim 2, wherein the
component includes a circulation mechanism that causes water inside
the container, or water flowed out through the water outlet port of
the container, to return upstream, such that a circulation flow
rate of water returning upstream is greater than a main stream flow
rate of water fed to the water heat exchanger.
4. The electrolysis device according to claim 3, wherein the
circulation flow rate is five times or more the main stream flow
rate.
5. The electrolysis device according to claim 3, further
comprising: an upstream main pathway that is connected to the water
inlet port of the container and that supplies water to the
container; and a downstream main pathway that is connected to the
water outlet port of the container and that feeds, to the water
heat exchanger, water that flows out of the water outlet port,
wherein the circulation mechanism has a circulation path and a
circulation pump that causes water to flow through the circulation
path; a first end of the circulation path is connected to the
container or the downstream main pathway; and a second end of the
circulation path is connected to a position, in the container,
upstream of a connection site of the first end, or to the upstream
main pathway.
6. The electrolysis device according to claim 2, wherein the
component includes a plurality of agitation members that are
arrayed along a direction of water flow, between the adjacent
electrodes.
7. The electrolysis device according to claim 6, wherein each of
the agitation members is formed of an insulating material.
8. The electrolysis device according to claim 6, wherein each of
the agitation members extends in a direction that intersects the
direction of water flow, in a state where gaps are formed between
the electrodes and each of the agitation members.
9. The electrolysis device according to claim 2, wherein the
component includes a stirrer that has a stirring blade disposed
inside the container, and a motor that is connected to the stirring
blade.
10. The electrolysis device according to claim 1, wherein the
plurality of electrodes include a first electrode plate, a second
electrode plate and a third electrode plate, each of which has a
plate shape, the first electrode plate, the second electrode plate
and the third electrode plate are arrayed in this order, spaced
apart from one another, in a plate thickness direction; a gap
between the first electrode plate and the second electrode plate
functions as a first flow channel through which water flows; a gap
between the second electrode plate and the third electrode plate
functions as a second flow channel through which water flows; and
the agitation part includes an inflow section provided in the
second electrode plate, part of water flowing through the first
flow channel flows into the second flow channel via the inflow
section.
11. The electrolysis device according to claim 10, wherein the
inflow section includes a plurality of through-holes provided in
the second electrode plate.
12. The electrolysis device according to claim 10, wherein the
inflow section includes a communicating section provided on an edge
of the second electrode plate.
13. The electrolysis device according to claim 10, wherein at least
one electrode plate from among the first electrode plate, the
second electrode plate and the third electrode plate has at least
either a plurality of projections that protrude towards an adjacent
electrode plate or a plurality of recesses that are recessed
towards a side opposite to an adjacent electrode plate.
14. The electrolysis device according to claim 1, wherein the
plurality of electrodes form a meandering flow channel through
which water flows while meandering inside the container.
15. A temperature-adjusting water-supplying apparatus, comprising:
a water heat exchanger that heats water; and the electrolysis
device according to claim 1, wherein the temperature-adjusting
water-supplying apparatus supplies water, the temperature of which
has been adjusted, in the water heat exchanger.
Description
TECHNICAL FIELD
[0001] The present invention relates to an electrolysis device, and
to a temperature-adjusting water-supplying apparatus, such as a
heat pump hot-water supply apparatus, a combustion-type hot-water
supply apparatus, an electric water warmer or a cooling tower,
which is provided with the electrolysis device.
BACKGROUND ART
[0002] Tap water and groundwater comprise components (scale
components) such as calcium ions, magnesium ions and the like, that
give rise to formation of scale. Therefore, scale in the form of
calcium salts (for instance, calcium carbonate), magnesium salts or
the like may precipitate in temperature-adjusting water-supplying
apparatus such as a water heater. Water that is heated in a water
heat exchanger of a temperature-adjusting water-supplying apparatus
is at a high temperature, and hence scale is particularly prone to
precipitate therein. When scale precipitates and becomes deposited
on the inner faces of pipes in the water heat exchanger, problems
occur in that, for instance, the performance of the water heat
exchanger is impaired, and flow channels in pipes become
narrower.
[0003] Patent Literature 1 discloses a combustion-type hot-water
supply apparatus provided with means for preventing generation of
scale. Patent Literature 2 proposes a technology wherein a scale
component in water is removed by electrolysis in an electrolysis
device that is provided upstream of a water heat exchanger of a
heat pump hot-water supply apparatus, with a view to suppressing
deposition of scale in the water heat exchanger. When water is
supplied into a container of this electrolysis device via a water
inlet port, in a state where voltage is applied to the water by an
electrode pair, scale such as calcium carbonate precipitates on the
cathode side of the electrode pair. As a result there is lowered
the concentration of scale component in the water that flows out of
the container via a water outlet port.
[0004] The efficiency of electrolysis in the electrolysis device
i.e. the efficiency with which the scale component is removed in
the electrolysis device must be increased in order to enhance the
effect of suppressing precipitation of scale in the water heat
exchanger. FIG. 12 of Patent Literature 2 discloses a technology
wherein water that has passed through an electrolysis device is
returned to upstream of the electrolysis device, and is caused to
flow again into the electrolysis device. The effect of enhancing
the removal efficiency of scale component may in some instances be
insufficient, however, when simply resorting to this disclosed
technology.
[0005] Means for increasing the removal efficiency of scale
component in electrolysis devices include, for instance, increasing
the surface area of the electrodes that come into contact with
water. However, the electrodes are formed of expensive materials
such as platinum, titanium or the like having excellent corrosion
resistance, and hence higher costs are incurred when the surface
area of the electrodes is increased in order to increase the
removal efficiency of scale component. [0006] Patent Literature 1:
Japanese Patent Application Publication No. 2001-317817 [0007]
Patent Literature 2: Japanese Patent Application Publication No.
2012-075982
SUMMARY OF INVENTION
[0008] It is an object of the present invention to provide an
electrolysis device that allows increasing the removal efficiency
of scale component while curtailing increases in cost derived from
electrode materials, and to provide a temperature-adjusting
water-supplying apparatus that comprises the electrolysis
device.
[0009] The electrolysis device of the present invention is for
removing a scale component contained in water that is fed to a
water heat exchanger. The electrolysis device comprises a container
having a water inlet port and a water outlet port, a plurality of
electrodes provided inside the container, and agitation means for
agitating water that flows between adjacent electrodes, between the
water inlet port and the water outlet port.
BRIEF DESCRIPTION OF DRAWINGS
[0010] FIG. 1 is a configuration diagram illustrating a heat pump
hot-water supply apparatus according to an embodiment of the
present invention.
[0011] FIG. 2 is a perspective view illustrating an electrolysis
device according to an embodiment of the present invention.
[0012] FIGS. 3A and 3B illustrate an electrolysis device according
to a first embodiment, wherein FIG. 3A is a cross-sectional diagram
of the electrolysis device cut along a plane parallel to a vertical
direction, and FIG. 3B is a cross-sectional diagram of the
electrolysis device cut along a plane parallel to a horizontal
direction.
[0013] FIG. 4A is a cross-sectional diagram of an enlarged portion
of FIG. 3A, and FIG. 4B is a cross-sectional diagram of an enlarged
portion of FIG. 3B.
[0014] FIG. 5 is a cross-sectional diagram illustrating Variation 1
of the electrolysis device of the first embodiment.
[0015] FIGS. 6A and 6B are cross-sectional diagrams illustrating
Variation 2 of the electrolysis device of the first embodiment,
wherein FIG. 6A is a cross-sectional diagram of the electrolysis
device of Variation 2 cut along a plane parallel to the vertical
direction, and FIG. 6B is a cross-sectional diagram of the
electrolysis device of Variation 2 cut along a plane parallel to
the horizontal direction.
[0016] FIG. 7 is a cross-sectional diagram illustrating Variation 3
of the electrolysis device of the first embodiment.
[0017] FIG. 8 is a cross-sectional diagram illustrating Variation 4
of the electrolysis device of the first embodiment.
[0018] FIG. 9 is a cross-sectional diagram illustrating Variation 5
of the electrolysis device of the first embodiment.
[0019] FIG. 10 is a cross-sectional diagram illustrating Variation
6 of the electrolysis device of the first embodiment.
[0020] FIG. 11A is a cross-sectional diagram of an electrolysis
device of a second embodiment cut along a plane parallel to a
vertical direction, and FIG. 11B is a cross-sectional diagram of
the electrolysis device of the second embodiment cut along a plane
parallel to a horizontal direction.
[0021] FIG. 12A is a front-view diagram illustrating an electrode
plate of the electrolysis device of the second embodiment, FIG. 12B
illustrates an electrode plate in Variation 1 of the electrolysis
device of the second embodiment, and FIG. 12C illustrates an
electrode plate in Variation 2 of the electrolysis device of the
second embodiment.
[0022] FIG. 13 is a perspective view diagram illustrating the
arrangement of a plurality of electrode plates, and the flow of
water, in the electrolysis device of the second embodiment.
[0023] FIG. 14 is a cross-sectional diagram illustrating the flow
of water inside a container in the electrolysis device of the
second embodiment.
[0024] FIG. 15 is a perspective view diagram illustrating the
arrangement of a plurality of electrode plates, and the flow of
water, in Variation 3 of the electrolysis device of the second
embodiment.
[0025] FIG. 16A is a front-view diagram illustrating an electrode
plate in Variation 4 of the electrolysis device of the second
embodiment, and FIG. 16B is a front-view diagram illustrating an
electrode plate in Variation 5 of the electrolysis device of the
second embodiment.
[0026] FIG. 17A is a front-view diagram illustrating an electrode
plate in Variation 6 of the electrolysis device of the second
embodiment, and FIG. 17B is a cross-sectional diagram along line
B-B of FIG. 17A.
[0027] FIG. 18A is a cross-sectional diagram illustrating the flow
of water inside a container in Variation 6, and FIG. 18B is a
cross-sectional diagram illustrating the flow of water inside a
container in Variation 7.
[0028] FIG. 19 is a cross-sectional diagram illustrating Variation
8 of the electrolysis device of the second embodiment.
[0029] FIG. 20 is a configuration diagram illustrating a heat pump
hot-water supply apparatus according to another embodiment of the
present invention.
[0030] FIGS. 21A and 21B are cross-sectional diagrams illustrating
an electrolysis device according to a third embodiment.
[0031] FIG. 22A is a cross-sectional diagram illustrating Variation
1 of the electrolysis device of the third embodiment, FIG. 22B is a
cross-sectional diagram illustrating Variation 2 of the
electrolysis device of the third embodiment, and FIG. 22C is a
cross-sectional diagram illustrating Variation 3 of the
electrolysis device of the third embodiment.
[0032] FIG. 23A is a cross-sectional diagram illustrating Variation
4 of the electrolysis device of the third embodiment, FIG. 23B is a
cross-sectional diagram illustrating Variation 5 of the
electrolysis device of the third embodiment, FIG. 23C is a
cross-sectional diagram illustrating Variation 6 of the
electrolysis device of the third embodiment, and FIG. 23D is a
cross-sectional diagram illustrating Variation 7 of the
electrolysis device of the third embodiment.
[0033] FIG. 24A is a cross-sectional diagram illustrating Variation
8 of the electrolysis device of the third embodiment, FIG. 24B is a
cross-sectional diagram illustrating Variation 9 of the
electrolysis device of the third embodiment, and FIG. 24C is a
cross-sectional diagram illustrating Variation 10 of the
electrolysis device of the third embodiment.
[0034] FIG. 25A is a cross-sectional diagram illustrating Variation
11 of the electrolysis device of the third embodiment, FIG. 25B is
a cross-sectional diagram illustrating Variation 12 of the
electrolysis device of the third embodiment, and FIG. 25C is a
cross-sectional diagram illustrating Variation 13 of the
electrolysis device of the third embodiment.
[0035] FIGS. 26A and 26B are cross-sectional diagrams illustrating
Variation 14 of the electrolysis device of the third
embodiment.
[0036] FIG. 27A is a side-view diagram illustrating Variation 15 of
the electrolysis device of the third embodiment, and FIG. 27B is a
cross-sectional diagram of the electrolysis device of Variation
15.
[0037] FIG. 28 is a schematic diagram illustrating the
configuration of a cooling tower, a combustion-type hot-water
supply apparatus or electric water warmer that is provided with the
electrolysis device of the first embodiment or the second
embodiment.
[0038] FIG. 29 is a schematic diagram illustrating the
configuration of a cooling tower, a combustion-type hot-water
supply apparatus or electric water warmer that is provided with the
electrolysis device of the third embodiment.
DESCRIPTION OF EMBODIMENTS
[0039] Heat Pump Hot-Water Supply Apparatus
[0040] A heat pump hot-water supply apparatus 11 according to an
embodiment of the present invention will be explained next with
reference to accompanying drawings. As illustrated in FIG. 1, the
heat pump hot-water supply apparatus 11 according to the present
embodiment is provided with a heat pump unit 13, a hot water
storage unit 17, an electrolysis device 41 and a controller 32 that
controls the foregoing.
[0041] The hot water storage unit 17 has a tank 15 that stores
water, a pump 31 and water conduits 27, 29. The tank 15 and the
water heat exchanger 21 are connected to each other by way of the
water conduits 27, 29. The water conduits 27, 29 include a water
inlet pipe 27 that has a feed-side flow channel through which water
from the tank 15 is fed to the water heat exchanger 21, and a hot
water outlet pipe 29 having a return-side flow channel through
which water heated in the water heat exchanger 21 through exchange
of heat, is returned to the tank 15. A pump 31 for feeding water is
provided in the water inlet pipe 27. The pump 31 causes water in
the tank 15 to flow out from a lower part of the tank 15 towards
the water inlet pipe 27, and to return to an upper part of the tank
15 by passing through the water inlet pipe 27, the water heat
exchanger 21 and the hot water outlet pipe 29, in this order.
[0042] The heat pump hot-water supply apparatus 11 is provided with
a refrigerant circuit 10a and a hot water storage circuit 10b. The
refrigerant circuit 10a comprises a compressor 19, a water heat
exchanger 21, a motor-operated expansion valve 23 as an expansion
mechanism, an air heat exchanger 25, and a refrigerant pipe that
connects the foregoing. The hot water storage circuit 10b comprises
the tank 15, the pump 31, the water heat exchanger 21, the
electrolysis device 41 and the water conduits 27, 29 that connect
the foregoing.
[0043] In the present embodiment, carbon dioxide is used as the
refrigerant that circulates through the refrigerant circuit 10a,
but the embodiment is not limited thereto. The refrigerant that
circulates through the refrigerant circuit 10a exchanges heat, in
the water heat exchanger 21, with water circulating through the hot
water storage circuit 10b, so that the water is heated as a result.
In the air heat exchanger 25, the refrigerant exchanges heat with
outside air and absorbs heat from the latter.
[0044] A water supply pipe 37 and a hot water supply pipe 35 are
connected to the tank 15. The hot water supply pipe 35 is connected
to an upper part of the tank 15. The purpose of the hot water
supply pipe 35 is to retrieve high-temperature water stored inside
the tank 15 and to supply hot water to a bathtub or the like. The
water supply pipe 37 is connected to the bottom of the tank 15. The
purpose of the water supply pipe 37 is to supply low-temperature
water from a water supply source into the tank 15. For instance,
tap water or groundwater such as well water can be used as the
water supply source that supplies water to the tank 15. The water
heater 11 in the present embodiment is a once-through water heater
wherein hot water supplied through the hot water supply pipe 35 is
not returned to the tank 15.
[0045] FIG. 2 is a plan-view diagram illustrating the electrolysis
device 41 according to an embodiment of the present invention. The
electrolysis device 41 is provided, in the water inlet pipe 27, at
a position downstream of the pump 31 and upstream of the water heat
exchanger 21. The purpose of the electrolysis device 41 is to
remove the scale component comprised in water that is fed to the
water heat exchanger 21. In a below-described first embodiment,
second embodiment and third embodiment, the electrolysis device 41,
takes on the shape such as the one illustrated in FIG. 2, but is
not limited thereto.
[0046] The electrolysis device 41 is provided with agitation means
for agitating, between adjacent electrodes, water that flows from
the water inlet port towards the water outlet port. The agitation
means may be configured out of a component separate from the
electrodes, or may be formed in the electrodes themselves. The
agitation means in the below-described first embodiment and third
embodiment is configured out of a component separate from the
electrodes. The agitation means in the below-described second
embodiment is formed in the electrodes themselves. The electrolysis
device 41 may combine the features of two or more embodiments
selected from among the first embodiment, the second embodiment and
the third embodiment. The electrolysis device 41 will be explained
in detail further on.
[0047] The controller 32 has a control unit 33 and a memory
(storage unit) 34. The control unit 33 controls a heat-up operation
of heating water in the tank 15, on the basis of a heat-up
operation schedule that is stored in the memory 34. The control
unit 33 controls for instance a power source 50 that supplies power
to the electric circuits of the electrolysis device 41 described
below. For instance, a DC power source is used as the power source
50.
[0048] The operation of the heat pump hot-water supply apparatus 11
will be explained next. In the heat-up operation of heating water
in the tank 15, the control unit 33 drives the compressor 19 of the
heat pump unit 13, regulates the degree of opening of the
motor-operated expansion valve 23, and drives the pump 31 of the
hot water storage unit 17. As a result, the low-temperature water
in the tank 15 is fed out through a water outlet that is provided
at the bottom of the tank 15, is fed to the water heat exchanger 21
via the water inlet pipe 27, and is heated in the water heat
exchanger 21, as illustrated in FIG. 1. The heated high-temperature
water passes through the hot water outlet pipe 29 and is returned
to the tank 15 through a water inlet that is provided at an upper
part of the tank 15. As a result, high-temperature water goes on
being sequentially stored in the tank 15, through the top of the
latter. In this heat-up operation, the scale component comprised in
the water is removed by the electrolysis device 41.
[0049] The heat pump hot-water supply apparatus 11 of the present
embodiment is a once-through water heater. In the once-through
water heater 11, the water (hot water) supplied through the hot
water supply pipe 35 is used by the user, and does not return to
the tank 15. Therefore, an amount of water that is substantially
identical to the amount of water supplied from the tank 15 via the
hot water supply pipe 35 is supplied herein to the tank 15 from the
water supply source, via the water supply pipe 37. That is, water
comprising a scale component from the water supply source, such as
tap water or well water, is replenished into the tank 15 at a high
frequency, and in a substantial replenishment amount. In the case
of a once-through heat pump hot-water supply apparatus, therefore,
the scale component must be removed more efficiently than in the
case of a cooling water circulation system of recirculating type,
or of a recirculating water heater.
Electrolysis Device
First Embodiment
[0050] FIG. 3A is a cross-sectional diagram of the electrolysis
device 41 illustrated in FIG. 2 cut along a plane parallel to the
vertical direction, and FIG. 3B is a cross-sectional diagram of the
electrolysis device 41 illustrated in FIG. 2 cut along a plane
parallel to the horizontal direction.
[0051] The electrolysis device 41 comprises a container 47 having a
water inlet port 43 and a water outlet port 45, a plurality of
first electrodes 51 and a plurality of second electrodes 52
disposed in the container 47, and an agitation unit 60 (see FIG.
4A), as agitation means. The agitation unit 60 will be explained
further on.
[0052] The first electrodes 51 and the second electrodes 52 are
formed of a material having excellent corrosion resistance.
Examples of the material that makes up the electrodes include
platinum, titanium and the like. The particulars are as
follows.
[0053] For instance the electrodes are formed of a material such
that at least the surface has platinum as a main component.
Specifically, the form of the electrodes may be such that the
entire electrode is formed of a material having platinum as a main
component (i.e. a material such as platinum or a platinum alloy).
The electrodes may be of a form wherein each electrode has an
electrode body formed out of a material having a greater ionization
tendency than that of platinum (i.e. a material that oxidizes more
readily in water than platinum), and a coating layer that is
formed, on the surface of the electrode body, out of a material
having platinum as a main component (i.e. a material such as
platinum or a platinum alloy). Examples of the material of the
electrode body include, for instance, materials having titanium as
a main component (i.e. a material such as titanium or a titanium
alloy).
[0054] The electrodes may be embodied as being formed, for
instance, out of a material having titanium as a main component
(i.e. titanium or a titanium alloy), as a material that oxidizes in
water more readily than platinum but that has comparatively
superior corrosion resistance.
[0055] The plurality of first electrodes 51 and the plurality of
second electrodes 52 are arrayed in one direction (thickness
direction of the electrodes) in such a manner that the first
electrodes 51 and the second electrodes 52 are disposed
alternately. The plurality of first electrodes 51 and the plurality
of second electrodes 52 are connected to the power source 50 in
such a manner that one of adjacent electrodes functions as an anode
and the other adjacent electrode functions as a cathode. Herein
adjacent electrodes 51, 52 make up a respective electrode pair 49.
In the present embodiment, the plurality of first electrodes 51 and
the plurality of second electrodes 52 are connected in parallel to
the power source 50, but the embodiment is not limited thereto. For
instance, a DC power source is used as the power source 50.
[0056] The electrodes may adopt various shapes, for instance a
plate shape or rod shape, but a plate shape is resorted to in the
present embodiment. The surface area of the electrodes can be made
greater as a result. The plurality of first electrodes 51 and the
plurality of second electrodes 52 in the present embodiment are
disposed parallel to each other, and are arrayed in the thickness
direction of the electrodes. Further, the plurality of first
electrodes 51 and the plurality of second electrodes 52 in the
present embodiment are disposed in such a manner that a meandering
flow channel is formed through which water flows while meandering,
inside the container 47. The particulars are as follows.
[0057] As illustrated in FIG. 2 and FIGS. 3A and 3B, the container
47 has a substantially rectangular parallelepiped shape made up of
six wall sections. These wall sections form a water flow space
through which water flows. The six wall sections include a first
wall section 471, a second wall section 472, a third wall section
473, a fourth wall section 474, a fifth wall section 475 and a
sixth wall section 476.
[0058] The first wall section 471 is positioned upstream in the
flow of water, and the second wall section 472 is positioned
downstream in the flow of water, at an attitude parallel to that of
the first wall section 471. The first wall section 471 and the
second wall section 472 are disposed parallel to the first
electrodes 51 and the second electrodes 52. The peripheral edges of
the first wall section 471 and the second wall section 472 are
joined by the third to sixth wall sections. The third wall section
473 is positioned on the lower side, and the fourth wall section
474 is positioned on the upper side, parallel to the third wall
section 473. The fifth wall section 475 is positioned at the right
as one faces downstream, and the sixth wall section 476 is
positioned at the left as one faces downstream, parallel to the
fifth wall section 475.
[0059] The water inlet port 43 of the container 47 is provided at a
lower part of the first wall section 471, and the water outlet port
45 is provided at an upper part of the second wall section 472. The
water inlet pipe 27 positioned on the pump 31 side is connected to
the water inlet port 43, and the water inlet pipe 27 positioned on
the water heat exchanger 21 side is connected to the water outlet
port 45. Water that is fed by the pump 31 to the electrolysis
device 41 via the water inlet pipe 27 flows through the water inlet
port 43 into the water flow space inside the container 47. Water
that has flowed into the water flow space flows then downstream in
the flow of water, and is discharged through the water outlet port
45 out of the container 47. The water outlet port 45 will be
explained further on.
[0060] The electrodes 51, 52 are arrayed along the horizontal
direction, spaced apart from each other in the thickness direction
of the electrodes. The gaps between electrodes function as a flow
channel through which water flows. Among the plurality of
electrodes 51, 52, the electrodes in contact with the third wall
section 473 and the electrodes in contact with the fourth wall
section 474 are juxtaposed alternately. Specifically, the first
electrodes 51 are in contact with the third wall section 473, and
extend towards the fourth wall section 474. Gaps through which
water can flow are provided between each of the first electrodes 51
and the inner face of the fourth wall section 474. The second
electrodes 52 are in contact with the fourth wall section 474, and
extend towards the third wall section 473. Gaps through which water
can flow are provided between each of the second electrodes 52 and
the inner face of the third wall section 473. A meandering flow
channel such as the one illustrated in FIG. 3A becomes formed as a
result inside the container 47.
[0061] In the present embodiment, the electrodes are disposed
parallel to a vertical direction, and hence the meandering flow
channel as well meanders in the vertical direction. The electrodes
may be disposed parallel to a direction that is oblique with
respect to the vertical direction. In this case, both the flow
channels in which water rises and the flow channel in which water
descends, in the meandering flow channel, extend in a direction
that is oblique with respect to the vertical direction.
[0062] In the electrolysis device 41 having such a structure, the
scale component in the water precipitates in the form of scale, by
electrolysis, on the cathode of each electrode pair that is made up
of adjacent electrodes, over the lapse of time until the water that
has flowed through the water inlet port 43 into the container 47
flows out of the container 47 through the water outlet port 45. The
scale deposited on the cathodes is caused to come off therefrom,
for instance through periodic reversal of the polarity of the
electrodes 51, 52, and to sediment on the third wall section 473 of
the container 47.
[0063] The agitation unit 60 will be explained next. The purpose of
the agitation unit 60 is to agitate the water that flows between
adjacent electrodes 51, 52 that make up an electrode pair 49. The
agitation unit 60 is a member separate from the electrodes. In the
present embodiment, the agitation unit 60 includes a plurality of
agitation members 61, as illustrated in FIGS. 4A and 4B.
[0064] The agitation members 61 in the present embodiment are
rod-like members having a columnar shape, but are not limited
thereto. The agitation members 61 that are used may be rod-like
members having a prismatic shape, or may have various shapes, as
illustrated for instance in Variations 1 and 2 described below.
[0065] The agitation members 61 extend in a direction that
intersects the direction of water flow (the direction denoted by
the arrows in FIG. 4A). In the present embodiment, the agitation
members 61 extend in a direction perpendicular to the direction of
water flow, and are disposed so as to be parallel to the electrodes
51, 52.
[0066] The plurality of agitation members 61 is provided between
adjacent electrodes 51, 52. The plurality of agitation members 61
is arrayed along the direction of water flow between adjacent
electrodes 51, 52. In the present embodiment, the plurality of
agitation members 61 in the flow channel of water includes a
plurality of first agitation members 61 disposed at positions
closer to the first electrodes 51 than the second electrodes 52,
and a plurality of second agitation members 61 disposed at
positions closer to the second electrodes 52 than the first
electrodes 51. In the present embodiment, the first agitation
members 61 and the second agitation members 61 are disposed
alternately along the direction of water flow, but are not limited
thereto.
[0067] As illustrated in FIG. 4B, one end of each of the agitation
members 61 of the present embodiment is supported on the fifth wall
section 475, while the other end is supported on the sixth wall
section 476. The agitation members 61 are disposed in a state where
a gap is left between the agitation members 61 and both electrodes
51, 52, but are not limited thereto. The agitation members 61 may
for instance be disposed in a state of being in contact with one of
the electrodes.
[0068] By providing a gap between the agitation members 61 and both
electrodes 51, 52, a pathway is created wherein the flow of water
that flows between the electrodes 51, 52 is split at the agitation
members 61, and the resulting flow paths merge again after having
passed the agitation members 61. That is, the water that flows
between the electrodes 51, 52 is agitated efficiently by being
repeatedly caused to split and merge on account of the plurality of
agitation members 61 that are arrayed, along the direction of water
flow, between the electrodes 51, 52.
[0069] In the present embodiment, as illustrated in FIG. 4B,
regions (gaps G) at which the agitation members 61 are not provided
are present between adjacent electrodes 51, 52, when the adjacent
electrodes 51, 52 and the plurality of agitation members 61 are
viewed in the direction of water flow (or a direction opposite to
the direction of water flow). Specifically, gaps G are provided
between a region at which the plurality of first agitation members
61 is arrayed, and a region at which the plurality of second
agitation members 61 is arrayed, as illustrated in FIG. 4B. Gaps G
are also provided between the first electrodes 51 and the region at
which the plurality of first agitation members 61 is arrayed, and
gaps G are likewise provided between the second electrodes 52 and
the region at which the plurality of second agitation members 61 is
arrayed. It becomes possible as a result to curtail increases in
the resistance to water flow (increases in pressure loss).
[0070] In the present embodiment, the plurality of agitation
members 61 is provided between adjacent electrodes 51, 52 in all
the electrode pairs 49, but the embodiment is not limited thereto.
For instance, a configuration may be adopted wherein the plurality
of agitation members 61 is provided between the electrodes 51, 52
in some of the electrode pairs 49, such that agitation members 61
are not provided between the electrodes 51, 52 of the remaining
electrode pairs 49.
[0071] The agitation members 61 are formed of an insulating
material, but are not limited thereto. Examples of insulating
materials include, for instance, insulating synthetic resins.
[0072] One example of the operating conditions at the time of
electrolysis in the present embodiment follows next. The flow rate
of water flowing into the container 47 via the water inlet port 43
is adjusted to be for instance, about 0.6 to 1.2 L/minute. The flow
velocity of the water flowing through the meandering flow channel
inside the container 47 is adjusted to about 6 to 13 mm/second. In
this case, the size of the flow channel (cross-sectional area
thereof) is adjusted in such a manner that the Reynolds number for
the flow of water in the meandering flow channel ranges from about
90 to about 200. The flow rate, flow velocity and Reynolds number
are examples of operating conditions, and are not limited to the
above ranges. The flow velocity and the Reynolds number are
adjusted so that a respective average value of values measured at a
plurality of sites in the meandering flow channel lies within the
above respective range. In a case where flow in the meandering flow
channel exhibits a flow velocity distribution, the flow velocity of
water that flows through the central section between the electrodes
51, 52 for which flow velocity is greatest is about twice as large
as the flow velocity of water that flows in the vicinity of these
electrodes.
[0073] Water flowing in the vicinity of the electrodes does not mix
readily with surrounding water in a case where the flow velocity of
water flowing through the meandering flow channel within the
container 47 is low, of about 6 to 13 mm/second, as in the present
embodiment. In conventional electrolysis devices that are not
provided with the agitation unit 60, water of low scale component
concentration is prone, in such a case, to drift to the vicinity of
those electrodes that function as anodes. In the present
embodiment, by contrast, it becomes possible to suppress drifting
of water of low scale component concentration towards the vicinity
of those electrodes that function as anodes, even at such low
velocity, and hence the precipitation reaction of the scale
component between the electrodes 51, 52 is accordingly
promoted.
[0074] FIG. 5 is a cross-sectional diagram illustrating Variation 1
of the electrolysis device 41. The shape of the agitation members
61 in Variation 1 differs from that in the embodiment illustrated
in FIGS. 4A and 4B. Only those features of Variation 1 that differ
from the features in the above embodiment illustrated in FIGS. 4A
and 4B will be explained herein. Features identical to those of the
embodiment will not be explained again.
[0075] As illustrated in FIG. 5, the agitation members 61 in
Variation 1 have a flat plate shape such that the dimension of the
agitation members 61 in the direction of water flow is smaller than
the dimension in the direction perpendicular to the direction of
water flow. The agitating effect on water is higher as a result in
Variation 1 than in the above embodiment.
[0076] FIGS. 6A and 6B are cross-sectional diagrams illustrating
Variation 2 of the electrolysis device 41. FIG. 6A is a
cross-sectional diagram of the electrolysis device 41 cut along a
plane parallel to the vertical direction, and FIG. 6B is a
cross-sectional diagram of the electrolysis device 41 cut along a
plane parallel to the horizontal direction. The shape of the
agitation members 61 in Variation 2 differs from that in the
embodiment illustrated in FIGS. 4A and 4B. Only those features of
Variation 2 that differ from the features in the above embodiment
illustrated in FIGS. 4A and 4B will be explained herein. Features
identical to those of the embodiment will not be explained
again.
[0077] As illustrated in FIGS. 6A and 6B, the agitation members 61
in Variation 2 have a shape that extends in a direction
perpendicular to the direction of water flow, between adjacent
electrodes 51, 52 that make up an electrode pair 49, while
meandering from the first electrode 51 towards the second electrode
52. The agitation members 61 are formed, for instance, through
bending of a rod-like member, having for example a columnar or
prismatic shape. The agitation members 61 may be configured by
being bent in the form of a coil.
[0078] FIG. 7 is a cross-sectional diagram illustrating Variation 3
of the electrolysis device 41. The configuration of the agitation
unit 60 in Variation 3 differs from that of the embodiment
illustrated in FIGS. 4A and 4B. The particulars are as follows.
[0079] In Variation 3, the agitation unit 60 comprises a plurality
of stirrers 64 each of which has a stirring blade 62 disposed
between adjacent electrodes 51, 52, and a motor 63 connected to the
stirring blade 62, as illustrated in FIG. 7. Each stirring blade 62
in Variation 3 is provided at a turn-back section of the meandering
flow channel. Further, each stirring blade 62 is provided at the
lower turn-back section, and is disposed in the vicinity of the
inner face of the third wall section 473. The rotation axes of the
stirring blades 62 point in the direction of water flow.
[0080] The stirring blades 62 are disposed at positions that enable
agitation of water from the third wall section 473 towards the
fourth wall section 474. Upon rotation of the stirring blades 62,
water in the vicinity thereof becomes agitated while being pushed
so as to flow towards the fourth wall section 474. In Variation 3,
specifically, parallel flow along the direction of water flow is
formed, by virtue of the rotation of the stirring blades 62, and
hence the flow of water inside the container 47 is smoother. The
stirring blades 62 may be provided at positions such that flow is
formed that runs against the direction of water flow.
[0081] The shape of the stirring blades 62 in Variation 3 may be,
for instance, of propeller type or turbine type, so long as it is a
shape that allows agitating water inside the container 47.
[0082] In Variation 3, the removal efficiency of scale component
can be enhanced while suppressing increases in power consumption in
the stirrers 64, if the rotational velocity of the stirring blades
62 is controlled in accordance with, for instance, the flow
velocity of water flowing between adjacent electrodes 51, 52 and
the value of current that flows in the electrodes 51, 52.
[0083] FIG. 8 is a cross-sectional diagram illustrating Variation 4
of the electrolysis device 41. The arrangement of the stirring
blades 62 in Variation 4 is different from that in Variation 3. The
particulars are as follows.
[0084] In Variation 4, as illustrated in FIG. 8, the agitation unit
60 has a plurality of stirring blades 62 that are arrayed along the
flow channel between the third wall section 473 and the fourth wall
section 474. The rotation axes of the stirring blades 62 point in a
direction perpendicular to the direction of water flow. The
stirring blades 62 are supported, for instance, on motor shafts,
not shown, that extend from the fifth wall section 475 towards the
sixth wall section 476.
[0085] FIG. 9 is a cross-sectional diagram illustrating Variation 5
of the electrolysis device 41. The shape of the electrodes 51, 52
in Variation 5 differs from that in the embodiment illustrated in
FIGS. 4A and 4B. The particulars are as follows.
[0086] As illustrated in FIG. 9, the electrodes in Variation 5 have
a wavy shape, and hence the electrodes 51, 52 elicit as well a
water agitation effect, in addition to the water agitation effect
by the plurality of agitation members 61.
[0087] In Variation 5, the pitch of the first electrodes 51, i.e.
the distance the between a ridge 51a and another ridge 51a of the
first electrodes 51, and the pitch of the second electrodes 52,
i.e. the distance between a ridge 52a and another ridge 52a of the
second electrodes 52, are identical. The same applies to troughs
51b, 52b. The adjacent first electrodes 51 and second electrodes 52
are disposed in such a manner that the flow channel width between
the foregoing is substantially constant throughout. The current
density within the electrode planes can be kept thereby
substantially constant. The flow channel is not prone to narrowing
on account of deposition of scale, since no locally narrow sites
are formed in the flow channel.
[0088] FIG. 10 is a cross-sectional diagram illustrating Variation
6 of the electrolysis device 41. As illustrated in FIG. 10,
Variation 6 differs from the embodiment illustrated in FIGS. 4A and
4B in that herein there is no meandering flow channel. The
particulars are as follows.
[0089] As illustrated in FIG. 10, the electrolysis device 41
comprises the container 47 that has the water inlet port 43 and the
water outlet port 45, and the first electrode 51 and the second
electrode 52 disposed in the container 47. In Variation 6, the
lower ends of the electrodes are spaced apart from the bottom
surface of the container 47, and the upper ends of the electrodes
are spaced apart from the upper surface of the container 47; hence,
there is no meandering flow channel such as the above-described
one. Therefore, the water that flows into the container 47 through
the water inlet port 43 flows thereupon, somewhat randomly, from
the water inlet port 43, through the interior of the container 47,
towards the water outlet port 45. The scale component is removed as
the water passes through the gaps between the adjacent electrodes
while in the way to the water outlet port 45.
[0090] In Variation 6, the agitation unit 60 is provided between
adjacent electrodes 51, 52. The agitation unit 60 has a plurality
of agitation members 61. The agitation members 61 that can be used
herein may be the agitation members 61 of the embodiment
illustrated in FIGS. 4A and 4B, the agitation members 61 of
Variation 1 illustrated in FIG. 5, or the agitation members 61 of
Variation 2 illustrated in FIG. 6.
[0091] In the embodiment illustrated in FIGS. 4A and 4B and the
variations thereof, as explained above, the electrolysis device 41
is provided with the agitation unit 60, and hence water flowing
between the electrodes 51, 52 is agitated by the agitation unit 60.
It becomes possible as a result to suppress drifting of water of
low scale component concentration towards the vicinity of those
electrodes that function as anodes, and hence the precipitation
reaction of the scale component between the electrodes 51, 52 is
accordingly promoted. Therefore, the removal efficiency of scale
component in the water can be enhanced even without increasing the
surface area of the electrodes by resorting to a means such as
increasing the number of electrodes or increasing the size of the
electrodes. Therefore, it becomes possible to enhance the removal
efficiency of scale component while curtailing increases in cost
derived from electrode materials.
[0092] In the embodiment illustrated in FIGS. 4A and 4B and
Variations 1, 2, 5 and 6, the agitation unit 60 includes the
plurality of agitation members 61 that are arrayed, between
adjacent electrodes 51, 52, in the direction of water flow. In
these configurations, the removal efficiency of scale component can
be enhanced by just resorting to a simple structure, namely an
array of a plurality of agitation members 61 along the direction of
water flow.
[0093] The agitation members 61 in the embodiment illustrated in
FIGS. 4A and 4B and Variations 1, 2, 5 and 6 are formed of an
insulating material, and hence are advantageous in terms of not
being corroded readily, even when subjected to an electrolytic
treatment over long periods of time in a state where the agitation
members 61 are disposed between adjacent electrodes 51, 52.
[0094] In the embodiment illustrated in FIGS. 4A and 4B and
Variations 1, 2, 5 and 6, the agitation members 61 extend, between
adjacent electrodes 51, 52, in a direction that intersects the
direction of water flow. The water flowing between the electrodes
51, 52 can be therefore agitated effectively. Moreover, the
agitation members 61 are disposed in a state where gaps are
provided between adjacent electrodes 51, 52, and hence water can be
agitated with good efficiency. By providing a gap between the
agitation members 61 and both electrodes 51, 52, a pathway is
created wherein the flow of water that flows between the electrodes
51, 52 is split at the agitation members 61, and the resulting flow
paths merge again after having passed the agitation members 61.
Water can be agitated as a result with good efficiency.
[0095] In Variations 3 and 4, the agitation unit 60 includes the
stirrers 64 that have stirring blades 62 disposed inside the
container 47, and the motors 63 connected to the stirring blades
62. Hence, the water inside the container 47 is forcibly agitated
by the stirring blades 62, and the effect of enhancing the removal
efficiency of scale component is therefore increased.
[0096] In the embodiment illustrated in FIGS. 4A and 4B and
Variations 1 to 5, the plurality of electrodes 51, 52 is
plate-shaped, and forms a meandering flow channel through which
water flows while meandering, inside the container 47. In these
configurations, therefore, the water that has flowed into the
container 47 through the water inlet port 43 flows along a
meandering pathway along the plate-shaped electrodes, from the
upstream side towards the downstream side. Therefore, the contact
surface area between the electrodes and the water increases, and
the removal efficiency of scale component can be further
enhanced.
Second Embodiment
[0097] The electrolysis device 41 of a second embodiment has an
inflow section as agitation means provided in the electrodes. FIG.
11A is a cross-sectional diagram of the electrolysis device 41
illustrated in FIG. 2 cut along a plane parallel to the vertical
direction, and FIG. 11B is a cross-sectional diagram of the
electrolysis device 41 illustrated in FIG. 2 cut along a plane
parallel to the horizontal direction.
[0098] The electrolysis device 41 comprises a container 47 having a
water inlet port 43 and a water outlet port 45, and a plurality of
electrode plates 51 to 5n accommodated in the container 47. The
electrode plates are formed of a material having excellent
corrosion resistance. The same material exemplified in the first
embodiment can be used as the material that makes up the electrode
plates.
[0099] The plurality of electrode plates 51 to 5n is made up of n
electrode plates that include a first electrode plate 51, a second
electrode plate 52, a third electrode plate 53 . . . and an n-th
electrode plate 5n. The plurality of electrode plates 51 to 5n is
arrayed in one direction (thickness direction of the electrode
plates). The plurality of electrode plates 51 to 5n is connected to
the power source 50 in such a manner that one electrode plate from
among adjacent electrode plates functions as an anode, and the
other adjacent electrode plate functions as a cathode (FIG. 11B).
Herein adjacent electrode plates make up a respective electrode
pair 49. In the present embodiment, the plurality of electrode
plates 51 to 5n is connected to the power source 50 in parallel,
but are not limited thereto. For instance, a DC power source is
used as the power source 50.
[0100] The electrode plates may adopt various plate shapes, for
instance a flat plate shape, a wavy plate shape or the like. The
surface area of the electrodes can be made greater as a result. The
flat plate shape is resorted to in the present embodiment. The
electrode plates 51 to 5n in the present embodiment are disposed
parallel to each other.
[0101] Inside the container 47 there are formed a first flow
channel F1, being a gap between a first electrode plate 51 and a
second electrode plate 52, and through which water flows in a first
direction D1, a second flow channel F2, being a gap between the
second electrode plate 52 and the third electrode plate 53, and
through which water flows in a second direction D2, opposite the
first direction D1, and a turn-back section T that connects the
downstream end of the first flow channel F1 and the upstream end of
the second flow channel F2.
[0102] Likewise hereafter, there is formed a k-th flow channel Fk
being a gap between a k-th electrode plate 5k and a (k+1)-th
electrode plate 5(k+1), and through which water flows in the second
direction D2, a (k+1)-th flow channel F(k+1) being a gap between
the (k+1)-th electrode plate 5(k+1) and a (k+2)-th electrode plate
5(k+2), and through which water flows in the first direction D1,
and a turn-back section T that connects a downstream end of the
k-th flow channel Fk and an upstream end of the (k+1)-th flow
channel F(k+1).
[0103] In the present embodiment, the boundary between the
turn-back section T and the downstream end of the flow channel Fk,
and the boundary between the turn-back section T and the upstream
end of the flow channel F(k+1) are positions denoted by the dashed
line L in the cross-sectional diagram of FIG. 14. The dashed line L
is a straight line parallel to the thickness direction of the
electrode plate 5(k+1) and that passes through the end of the
electrode plate 5(k+1) (end adjacent to the turn-back section
T).
[0104] The plurality of electrode plates 51 to 5n in the present
embodiment is disposed in such a manner that a meandering flow
channel is formed, through which water flows while meandering,
inside the container 47. The particulars are as follows.
[0105] As illustrated in FIG. 2 and FIGS. 11A and 11B, the
container 47 has a substantially rectangular parallelepiped shape
made up of six wall sections. These wall sections form a water flow
space through which water flows. The six wall sections include a
first wall section 471, a second wall section 472, a third wall
section 473, a fourth wall section 474, a fifth wall section 475
and a sixth wall section 476.
[0106] The first wall section 471 is positioned upstream in the
flow of water, and the second wall section 472 is positioned
downstream in the flow of water, parallel to the first wall section
471. The first wall section 471 and the second wall section 472 are
disposed parallel to the first electrode plate 51 and the second
electrode plate 52. The peripheral edges of the first wall section
471 and the second wall section 472 are joined by the third to
sixth wall sections. The third wall section 473 is positioned on
the lower side, and the fourth wall section 474 is positioned on
the upper side, parallel to the third wall section 473. The fifth
wall section 475 is positioned at the right as one faces
downstream, and the sixth wall section 476 is positioned at the
left as one faces downstream, parallel to the fifth wall section
475.
[0107] The water inlet port 43 of the container 47 is provided at a
lower part of the first wall section 471, and the water outlet port
45 is provided at an upper part of the second wall section 472. The
water inlet pipe 27 positioned on the pump 31 side is connected to
the water inlet port 43, and the water inlet pipe 27 positioned on
the water heat exchanger 21 side is connected to the water outlet
port 45. Water that is fed by the pump 31 to the electrolysis
device 41 via the water inlet pipe 27 flows through the water inlet
port 43 into the water flow space inside the container 47. Water
that has flowed into the water flow space flows then downstream in
the flow of water, and is discharged through the water outlet port
45 out of the container 47.
[0108] The electrode plates 51 to 5n are arrayed along the
horizontal direction spaced apart from each other in the thickness
direction of the electrode plates. The gaps between electrode
plates function as the flow channel F1 to F(n-1) through which
water flows. Among the plurality of electrode plates 51 to 5n, the
electrode plates in contact with the third wall section 473 and the
electrode plates in contact with the fourth wall section 474 are
juxtaposed alternately. Specifically, the former electrode plates
52, 54, . . . 5n are in contact with the third wall section 473,
and extend towards the fourth wall section 474. Gaps through which
water can flow are provided between the electrode plates and the
inner face of the fourth wall section 474, so that turn-back
sections T are formed as a result. The electrode plates 51, 53, . .
. , 5(n-1) of the latter are in contact with the fourth wall
section 474, and extend towards the third wall section 473. Gaps
through which water can flow are provided between the electrode
plates and the inner face of the third wall section 473, so that
turn-back sections T are formed as a result. A meandering flow
channel such as the one illustrated in FIG. 11A becomes formed as a
result inside the container 47.
[0109] In the electrolysis device 41 having such a structure, the
scale component in the water precipitates in the form of scale, by
electrolysis, on the cathode of each electrode pair 49 that is made
up of adjacent electrode plates, over the lapse of time until the
water that has flowed through the water inlet port 43 into the
container 47 flows out of the container 47 through the water outlet
port 45. The scale deposited on the cathodes is caused to come off
therefrom, for instance through periodic reversal of the polarity
of the electrode plates, and to sediment on the third wall section
473 of the container 47.
[0110] The electrode plates will be explained in further detail
next with reference to FIGS. 12A and 12B. Herein, FIG. 12A is a
front-view diagram illustrating an electrode plate of the
electrolysis device 41. The electrode plates have an inflow section
as agitation means. The inflow section has a plurality of
communicating sections C. The particulars are as follows.
[0111] As illustrated in FIG. 12A, for instance the electrode plate
5k has a plurality of communicating sections C. The communicating
sections C are through-holes (water passage holes) that penetrate
through the electrode plate 5k in the thickness direction thereof.
The communicating sections C are not limited circular
through-holes, and may have a square or rectangular shape, such as
the one of Variation 1 illustrated in FIG. 12B, or may have a
rhomboid shape such as the one of Variation 2 illustrated in FIG.
12C.
[0112] The communicating sections C are provided spaced apart from
each other. Adjacent communicating sections C are provided spaced
apart from each other in the first direction D1 or in a direction
that intersects the first direction D1. In the present embodiment,
the communicating sections C are provided, distributed at intervals
from each other, substantially over the entirety of the electrode.
The communicating sections C are provided at equal intervals
substantially, over the entirety of the electrode plate 5k, but the
embodiment is not limited thereto. For instance, the number and/or
opening surface area of the communicating sections C in the
electrode plate 5k, at an opposing region that opposes an adjacent
electrode plate 5(k+1) in the thickness direction of the electrode
plates, may be set to be greater than the number or opening surface
area of the communicating sections C at a region other than that
opposing region.
[0113] In the present embodiment, the number of the communicating
sections C and the size of the communicating sections C are
identical among the plurality of electrode plates 51 to 5n, but the
embodiment is not limited thereto. For instance, the concentration
of the scale component in water on the downstream side in the
interior of the container 47 tends to be smaller than that on the
upstream side, and hence the number of the communicating sections C
in downstream electrode plates may be set to be greater than the
number of the communicating sections C in upstream electrode
plates. Also, the opening surface area of the communicating
sections C in downstream electrode plates may be set to be larger
than the opening surface area of the communicating sections C in
upstream electrode plates.
[0114] The number, opening surface area and so forth of the
plurality of communicating sections C provided in the electrode
plate 5k are not particularly limited. Preferably, the total
opening surface area of the plurality of communicating sections C
provided in the electrode plate 5k is equal to or smaller than 5%
of the surface area of one surface of the electrode plate 5k
(surface area assuming that no communicating sections C are
provided in the electrode plate 5k). As a result, it becomes
possible to disturb the flow of water in the flow channel between
electrode plates while curtailing decreases in the surface area of
the electrode plates. Preferably, the total of the opening surface
area of the communicating sections C ranges from 1% to 3% of the
surface area of the electrode plate 5k.
[0115] FIG. 13 is a perspective view diagram illustrating the
arrangement of a plurality of electrode plates and flow of water
inside the container 47, and FIG. 14 is a cross-sectional diagram
illustrating the flow of water inside the container 47. As
illustrated in FIG. 13 and FIG. 14, part of the water flowing
through the flow channel F(k-1) in the first direction D1 (upwards)
flows into the flow channel Fk via the communicating sections C
provided in the electrode plate 5k, and becomes mixed with the main
stream that flows through the flow channel Fk. The flow of water in
the flow channel Fk is disturbed as a result. Similarly, part of
the water flowing through the flow channel Fk in the second
direction D2 (downwards) flows into the flow channel F(k+1) through
the communicating sections C that are provided in the electrode
plate 5(k+1), and becomes mixed with the main stream that flows
through the flow channel F(k+1). The flow of water in the flow
channel F(k+1) is disturbed as a result.
[0116] The operating conditions in the second embodiment at the
time of electrolysis are identical to the operating conditions
explained for the first embodiment, and will not be described
again. As in the second embodiment, water flowing through the
vicinity of the electrode plates does not mix readily with
surrounding water in a case where the flow velocity of water
flowing through the meandering flow channel within the container 47
is low, of about 6 to 13 mm/second. In such a case, water of low
scale component concentration is prone to drift to the vicinity of
those electrode plates that function as anodes, in conventional
electrolysis devices in which the electrode plates do not have the
plurality of communicating sections C. In the present embodiment,
by contrast, it becomes possible to suppress drifting of water of
low scale component concentration towards the vicinity of those
electrode plates that function as anodes, even at such low
velocity, and hence the precipitation reaction of the scale
component between the electrode plates is accordingly promoted.
[0117] In the present embodiment, an instance has been exemplified
wherein the plurality of electrode plates 51 to 5n forms a
meandering flow channel that meanders in the vertical direction,
inside the container 47, but the embodiment is not limited thereto.
For instance, the plurality of electrode plates 51 to 5n may adopt
a configuration such that the electrode plates 51 to 5n form a
meandering flow channel that meanders in some other direction, for
instance a horizontal direction, inside the container 47.
[0118] To form a meandering flow channel that meanders in the
horizontal direction, for instance, it suffices to arrange the
electrolysis device 41 illustrated in FIGS. 11A and 11B in such a
manner that the fifth wall section 475 is positioned on the lower
side and the sixth wall section 476 is positioned on the upper
side. In this case, part of the water that flows through the flow
channel F(k-1) in the first direction D1 (rightwards) flows into
the flow channel Fk through the communicating sections C provided
in the electrode plate 5k, and merges with the main stream that
flows through the flow channel Fk, as illustrated in Variation 3 of
FIG. 15. The flow of water in the flow channel Fk is disturbed as a
result. Similarly, part of the water flowing through the flow
channel Fk in the second direction D2 (leftwards) flows into the
flow channel F(k+1) through the communicating sections C that are
provided in the electrode plate 5(k+1), and merges with the main
stream that flows through the flow channel F(k+1). The flow of
water in the flow channel F(k+1) is disturbed as a result.
[0119] FIG. 16A is a front-view diagram illustrating an electrode
plate in Variation 4 of the electrolysis device 41. In Variation 4,
as illustrated in FIG. 16A, some of the communicating sections C1
from among the plurality of communicating sections C are provided
at an edge E1, of the electrode plate 5k, adjacent to a turn-back
section T. These communicating sections C1 are provided spaced
apart from each other along the edge E1. These communicating
sections C1 are not through-holes such that the periphery whereof
is closed, as in the case of the other communicating sections C,
but are, instead, through-sections such that part of the opening
thereof is open at the edge E1.
[0120] In Variation 4, some communicating sections C2 from among
the plurality of communicating sections C are provided at edges E2
on both sides of the electrode plate 5k. These communicating
sections C2 are provided spaced apart from each other along the
edges E2. Unlike the other communicating sections C, the
communicating sections C1 are not through-holes having the
periphery that is closed, but are through-sections having the
opening that is partially opened at the edges E2. Electrode plates
other than the electrode plate k may also have a configuration
identical to that of the electrode plate k.
[0121] FIG. 16B is a front-view diagram illustrating an electrode
plate in Variation 5 of the electrolysis device 41. In Variation 5,
the electrode plate 5k has a plurality of slits (communicating
sections) C. The slits C extend in a direction that intersects the
direction of water flow D1 or D2. In this variation, the slits C
extend in a direction that is perpendicular to the direction of
water flow D1 or D2. Some slits C2 from among the plurality of
slits C are opened at the edges E2 positioned at the sides.
Electrode plates other than the electrode plate k may also have a
configuration identical to that of the electrode plate k.
[0122] FIG. 17A is a front-view diagram illustrating an electrode
plate in Variation 6 of the electrolysis device 41, and FIG. 17B is
a cross-sectional diagram along line B-B of FIG. 17A. As
illustrated in FIGS. 17A and 17B, the electrode plates in Variation
6 have a plurality of projections 66 that protrude towards an
adjacent electrode plate on one side in the thickness direction,
and a plurality of recesses 65 that are recessed towards the side
opposite to an adjacent electrode plate on the other side in the
thickness direction.
[0123] In Variation 6, the plurality of recesses 65 and plurality
of projections 66 are formed through working a sheet metal material
in such a manner that one face of the metal sheet material is sunk,
whereby the other face thereof bulges out. The plurality of
recesses 65 and plurality of projections 66 formed on the electrode
plates are formed at identical positions, but on mutually reverse
faces, of the electrode plates. The shapes of the recesses 65 in
Variation 6 are semispherical shapes that are recessed in the
thickness direction of the electrodes, and the shapes of the
projections 66 are semispherical shapes that protrude in the
thickness direction of the electrodes, but may be other shapes, for
instance columnar, or prismatic shapes.
[0124] The recesses 65 (projections 66) in the electrode plates are
provided spaced apart from each other. In Variation 6, the
plurality of recesses 65 (plurality of projections 66) is arrayed
regularly, lengthwise and breadthwise, over the entire surface of
the electrodes, but a respective density of the recesses 65
(projections 66) may be set for each given region in a case where,
for instance, there are certain regions at which the agitation
effect is to be focused to a greater degree than in other
regions.
[0125] FIG. 18A is a cross-sectional diagram illustrating the flow
of water inside the container 47 in Variation 6. As illustrated in
FIG. 18A, the flow of water in the flow channels between adjacent
electrode plates in Variation 6 is disturbed by the plurality of
projections 66 and the plurality of recesses 65. As a result, it
becomes possible to further suppress drifting of water of low scale
component concentration towards the vicinity of those electrode
plates that function as anodes, from among adjacent electrode
plates, and hence the precipitation reaction of the scale component
between the electrode plates is further promoted.
[0126] In Variation 6, for instance, some or all the projections 66
of the electrode plate 5(k+1) are provided at positions that
oppose, in the thickness direction of the electrode plates, the
communicating sections C that are provided in the electrode plate
5k, but the projections 66 may be offset to some extent with
respect to the communicating sections C. The projections 66
protrude towards an electrode plate that is positioned upstream. In
this case, the flow of water can be disturbed yet more effectively
by virtue of a synergistic effect that combines the effect of
disturbing the flow of water elicited by water that flows into the
flow channel Fk via the communicating sections C that are provided
in the electrode plate 5k, and the effect of disturbing the flow of
water elicited by the projections 66 that are at positions opposing
those of the communicating sections C.
[0127] The projections 66 may protrude towards an electrode plate
that is positioned downstream, as in Variation 7 illustrated in
FIG. 18B. In Variation 7, for instance at least some of the
plurality of projections 66 in the electrode plate 5k are provided
at a position at which the inflow of water into the flow channel
F(k+1) via the communicating sections C is promoted. Specific
examples of the position at which inflow of water to the flow
channel F(k+1) via the communicating sections C is promoted
include, for instance, positions of the projections 66 such that
water that flows through the flow channel Fk is guided, by flowing
along the projections 66, into the communicating sections C that
are provided in the electrode plate 5(k+1), as denoted by arrows G
in FIG. 18B.
[0128] In Variation 7, for instance, some or all the projections 66
of the electrode plate 5k are provided at positions that oppose, in
the thickness direction of the electrode plates, the communicating
sections C that are provided in the electrode plate 5(k+1), but the
projections 66 may be offset to some extent with respect to the
communicating sections C.
[0129] FIG. 19 is a cross-sectional diagram illustrating Variation
8 of the electrolysis device 41. In Variation 8, the electrolysis
device 41 is provided with the container 47, the first electrode
plate 51, the second electrode plate 52 and the third electrode
plate 53 that are accommodated in the container 47, and with the
power source 50. The first electrode plate 51, the second electrode
plate 52 and the third electrode plate 53 are arrayed in this
order, spaced apart from each other, in the thickness direction of
the electrode plates. Inside the container 47 there are formed the
first flow channel F1, being a gap between the first electrode
plate 51 and the second electrode plate 52, and through which water
flows in the first direction D1, the second flow channel F2, being
a gap between the second electrode plate 52 and the third electrode
plate 53, and through which water flows in a second direction D2
opposite the first direction D1, and the turn-back section T that
connects the downstream end of the first flow channel F1 and the
upstream end of the second flow channel F2. The second electrode
plate 52 has the plurality of communicating sections C for causing
part of the water flowing through the first flow channel F1 to flow
into the second flow channel F2, upstream of the downstream end of
the first flow channel F1. The communicating sections C are not
provided in the first electrode plate 51 or the third electrode
plate 53.
[0130] In the second embodiment and variations thereof, as
explained above, the plurality of communicating sections C are
provided in the electrode plates. Therefore, part of the water
flowing through the first flow channel F1 flows into the second
flow channel F2 via the plurality of communicating sections C,
upstream of the downstream end of the first flow channel first flow
channel F1. As a result, the inflowing water is mixed, at a
plurality of sites, with water flowing through the second flow
channel F2. Such mixing of water at a plurality of sites causes the
flow of water through the second flow channel F2 to be effectively
disturbed over a wide range. As a result, it becomes possible to
effectively suppress drifting of water of low scale component
concentration towards the vicinity of that electrode plate that
functions as an anode, from among the second electrode plate 52 and
the third electrode plate 53 that form the second flow channel F2,
and hence the precipitation reaction of the scale component between
the second electrode plate 52 and the third electrode plate 53 is
accordingly promoted.
[0131] Further, the flow of water that flows in the vicinity of the
communicating sections C is disturbed, also in the first flow
channel F1, when part of the water that flows through the first
flow channel F1 flows out of the first flow channel F1 via the
plurality of communicating sections C, as described above. As a
result, it becomes possible to effectively suppress drifting of
water of low scale component concentration towards the vicinity of
that electrode plate that functions as an anode, from among the
first electrode plate 51 and the second electrode plate 52 that
form the first flow channel F1, and hence the precipitation
reaction of the scale component between the first electrode plate
51 and the second electrode plate 52 is accordingly promoted.
[0132] Such being the case, this configuration allows increasing
the removal efficiency of scale component in water, even without
increasing the surface area of the electrode plates by increasing
the number of electrode plates. Therefore, it becomes possible to
increase the removal efficiency of scale component while curtailing
increases in cost derived from electrode materials.
[0133] In these configurations, as described above, the water that
flows into the container 47 through the water inlet port 43 flows
in the first direction D1, through the first flow channel F1,
towards the turn-back section T; thereupon, the direction of flow
is reversed at the turn-back section T, and thereafter the water
flows through the second flow channel F2 in the second direction
D2. Thus, pressure loss occurs when water flows through the first
flow channel F1, the turn-back section T and the second flow
channel F2 in this order, and, accordingly, the pressure in the
second flow channel F2 becomes lower than the pressure in the first
flow channel F1. As a result, water flows from the first flow
channel F1 into the second flow channel F2 via the communicating
sections C.
[0134] In the second embodiment and variations thereof, adjacent
communicating sections C are provided spaced apart from each other,
in the electrode plates, in the first direction D1 or in a
direction that intersects the first direction D1. In this
configuration, for instance, part of the water that flows through
the first flow channel F1 in the first direction D1 flows into the
second flow channel F2 via the plurality of communicating sections
C that are provided, spaced apart from each other, in the first
direction D1 or a direction that intersects the first direction D1.
In the second flow channel F2, therefore, the flow of water is
effectively disturbed over a wide range in the first direction D1
or a direction that intersects the first direction D1.
[0135] In the second embodiment and Variations 1 to 7, the
plurality of communicating sections C is provided not only in the
second electrode plate 52 but in other electrode plates as well,
and hence mixing of water in the flow channels F1 to F(n-1)
(disturbing of the flow of water) is further promoted.
[0136] In Variation 4, some of the plurality of communicating
sections C are provided at the edge E1 of the of the electrode
plates that are adjacent to the turn-back sections T. In this
configuration, therefore, water flows into the downstream flow
channel via the communicating sections C that are provided at the
edge E1 of the electrode plates. Such water inflow disturbs the
flow of water at the turn-back sections T, and the flow of water
from each turn-back section T into the flow channel downstream
thereof. Therefore, the water that flows from each turn-back
section T into the flow channel downstream thereof exhibits a
smaller difference between the scale component concentration at a
region on the side of one electrode plate that makes up the flow
channel and the scale component concentration at a region on the
side of the other electrode plate. That is, there decreases the
difference in concentration of scale component in the width
direction of the flow channel. As a result, it becomes possible to
further suppress drifting of water of low scale component
concentration towards the one electrode plate and the other
electrode plate in the flow channel.
[0137] In Variations 6 and 7, each of the electrode plates has the
plurality of projections 66 that protrude towards an adjacent
electrode plate, and the plurality of recesses 65 that are recessed
towards a side opposite to an adjacent electrode plate. In this
configuration, the flow of water in the flow channel between
adjacent electrode plates is disturbed by the plurality of
projections 66 and the plurality of recesses 65. As a result, it
becomes possible to further suppress drifting of water of low scale
component concentration towards the vicinity of that electrode
plate that functions as an anode, from among the adjacent electrode
plates. Therefore, the precipitation reaction of scale component
between electrode plates is further promoted.
[0138] In Variation 7, the projections 66 protrude towards the
electrode plates that are positioned downstream. In Variation 7, at
least some of the plurality of projections 66 in the electrode
plate 5k are provided at positions at which there is promoted
inflow of water into the flow channel F(k+1) via the communicating
sections C. In this configuration, inflow of water to flow channel
F(k+1) via the communicating sections C is promoted by the
projections 66, and hence the effect of disturbing the flow of
water at the flow channel F(k+1) is further increased.
[0139] In Variation 5, the plurality of communicating sections C
has a plurality of slits. In this configuration, the amount of
water that flows into the flow channel F2 via the communicating
sections C can be adjusted by adjusting the size of the slits in
the longitudinal direction thereof.
[0140] In Variation 5, the slits extend in a direction that
intersects the direction of water flow. In this configuration,
water can be caused to flow into the flow channel, in the direction
that intersects the direction of water flow, over a wider range
than in the case where the longitudinal direction of the slits
extends in a direction parallel to the direction of water flow.
Third Embodiment
[0141] The electrolysis device 41 according to the third embodiment
differs from those of the first embodiment and the second
embodiment in that now the electrolysis device 41 is further
provided with a circulation mechanism 80 as agitation means, as
illustrated in FIG. 20. Herein, FIGS. 21A and 21B are
cross-sectional diagrams illustrating the electrolysis device 41
according to the third embodiment. FIG. 21A is a cross-sectional
diagram of the electrolysis device 41 illustrated in FIG. 2 cut
along a plane parallel to the vertical direction, wherein the
cross-section of the electrolysis device 41 is depicted as a side
view. FIG. 21B is a cross-sectional diagram of the electrolysis
device 41 illustrated in FIG. 2 cut along a plane parallel to the
horizontal direction, wherein the cross-section of the electrolysis
device 41 is depicted as a plane view.
[0142] As illustrated in FIGS. 21A and 21B, the electrolysis device
41 has a container 47 and a plurality of electrodes 51, 52 provided
inside the container 47. As illustrated in FIG. 21B, a water flow
channel is formed by the plurality of electrodes 51, 52, inside the
container 47. In the present embodiment, the water flow channel is
a single meandering flow channel formed by the plurality of
electrodes 51, 52, but is not limited thereto. The water flow
channel may be a flow channel that is not a meandering flow
channel, for instance as in the below-described Variation 15
illustrated in FIGS. 27A and 27B. The meandering flow channel in
the present embodiment meanders in the horizontal direction, as
illustrated in FIG. 21B, but is not limited thereto. The meandering
flow channel may, for instance, meander in the vertical
direction.
[0143] In the present embodiment, the container 47 has a
substantially rectangular parallelepiped shape, but is not limited
thereto. A water flow space through which water flows is provided
inside the container 47. The container 47 has a first wall section
471 and a second wall section 472 opposing each other. The
container 47 has side wall sections that join the first wall
section 471 and the second wall section 472. In the present
embodiment, the side wall section include, although not limited
thereto, a third wall section 473 that makes up a lower wall, a
fourth wall section 474 that makes up an upper wall, a fifth wall
section 475 that makes up a left wall, and a sixth wall section 476
that makes up a right wall.
[0144] The container 47 has a water inlet port 43 and a water
outlet port 45. The water inlet port 43 of the container 47 is
provided in the first wall section 471, and the water outlet port
45 is provided in the second wall section 472, but the embodiment
is not limited thereto. One or both of the water inlet port 43 and
the water outlet port 45 may be provided at the side wall sections
above. The water inlet pipe 27 positioned on the side of the tank
15 illustrated in FIG. 20 (upstream main pathway 27A) is connected
to the water inlet port 43, while the water inlet pipe 27
positioned on the side of the water heat exchanger 21 illustrated
in FIG. 20 (downstream main pathway 27B) is connected to the water
outlet port 45.
[0145] The plurality of electrodes 51, 52 comprises a plurality of
first electrodes 51 and a plurality of second electrodes 52. The
plurality of first electrodes 51 and the plurality of second
electrodes 52 are arrayed in one direction (thickness direction of
the electrodes) in such a manner that the first electrodes 51 and
the second electrodes 52 are disposed alternately. In the present
embodiment, the plurality of first electrodes 51 extends from the
third wall section 473 towards the fourth wall section 474, as
illustrated in FIG. 21B, and the plurality of second electrodes 52
extends from the fourth wall section 474 towards the third wall
section 473. In the present embodiment, the electrodes are disposed
at an attitude parallel to the first wall section 471, but the
embodiment is not limited thereto.
[0146] Herein adjacent electrodes 51, 52 make up a respective
electrode pair 49. The plurality of electrodes 51, 52 is connected
to a power source, not shown, in such a manner that one electrode
of each electrode pair 49 functions as an anode and the other
electrode functions as a cathode. Herein, a DC power source is used
for instance as the power source. In the present embodiment, the
plurality of first electrodes 51 and the plurality of second
electrodes 52 are connected in parallel to the power source 50, but
the embodiment is not limited thereto.
[0147] The same material exemplified in the first embodiment can be
used as the material that makes up the electrode plates.
[0148] The electrodes may adopt various shapes, for instance a
plate shape or rod shape, but a flat plate shape is resorted to in
the present embodiment. The surface area of the electrodes can be
made greater as a result. The plurality of first electrodes 51 and
the plurality of second electrodes 52 in the present embodiment are
disposed at mutually parallel attitudes, and are arrayed spaced
apart from each other in the thickness direction of the electrodes.
The gaps between electrodes function as flow channel through which
water flows. In the present embodiment, the plurality of first
electrodes 51 and the plurality of second electrodes 52 are
disposed in such a manner that a meandering flow channel is formed,
inside the container 47, through which water flows while
meandering.
[0149] Voltage is applied to the electrode pairs 49 of the
electrolysis device 41 during the heat-up operation of heating the
water in the tank 15. Examples of electrolysis conditions in the
electrolysis device 41 include for instance, although not limited
thereto, a condition whereby current of a preset current value
flows in the electrode pairs 49, a condition whereby a preset
voltage is applied to the electrode pairs 49, or a condition that
combines the foregoing conditions.
[0150] During the heat-up operation, the scale component comprised
in water precipitates as scale, on the cathode of the electrode
pairs 49, over the lapse of time until the water that has flowed
into the container 47 through one from among the water inlet port
43 and the water outlet port 45 flows out of the container 47
through the other from among the water inlet port 43 and the water
outlet port 45. As a result, it becomes possible to feed, to the
water heat exchanger 21, water having had the scale component
concentration thereof lowered in the electrolysis device 41.
[0151] The circulation mechanism 80 has the function of returning,
to the upstream side, water inside the container 47, or water that
has flowed out of the water outlet port 45 of the container 47. The
circulation mechanism 80 comprises a circulation path (circulation
pipe) 81 and a circulation pump (water pump) 82 that causes water
to flow through the circulation path 81.
[0152] The circulation path 81 has a first end (circulating water
inlet port end) 81a and a second end (circulating water outlet port
end) 81b. The circulation pump 82 is provided at the circulation
path 81.
[0153] In the present embodiment illustrated in FIG. 21A, the first
end 81a and the second end 81b of the circulation path 81 are both
connected to the container 47 of the electrolysis device 41. The
second end 81b is positioned upstream of the site of connecting the
first end 81a to the container 47.
[0154] In the present embodiment, specifically, the first end 81a
is positioned closer to the second wall section 472 than the
electrode that is furthest downstream. The second end 81b is
positioned closer to the first wall section 471 than the electrode
that is furthest upstream. In the present embodiment, the first end
81a and the second end 81b are not disposed in the water flow
channel between the electrodes 51, 52, but at a region other than
the water flow channel between the electrodes 51, 52.
[0155] In the present embodiment illustrated in FIG. 21A, the first
end 81a and the second end 81b are positioned inside the container
47, but the embodiment is not limited thereto. One or both of the
first end 81a and the second end 81b may be for instance connected
to a joint, not shown, that protrudes outward from a wall section
of the container 47, in which case one or both of the first end 81a
and the second end 81b are positioned outside the container 47.
This feature applies also to the below-described variations.
[0156] A space S1 is provided between the electrode furthest
downstream and the wall section that opposes this electrode (second
wall section 472 in the present embodiment). The first end 81a is
connected to the wall section (third wall section 473 in the
present embodiment) that delimits the space S1. Water in the space
S1 flows into the circulation path 81 via the first end 81a. A
space S2 is provided between the electrode furthest upstream and
the wall section that opposes this electrode (first wall section
471 in the present embodiment). The second end 81b is connected to
the wall section (third wall section 473 in the present embodiment)
that delimits the space S2. Circulating water that flows through
the circulation path 81 flows into the space S2 via the second end
81b.
[0157] The first end 81a may be connected to the second wall
section 472, the fourth wall section 474, the fifth wall section
475 or the sixth wall section 476, and the second end 81b may be
connected to the first wall section 471, the fourth wall section
474, the fifth wall section 475 or the sixth wall section 476.
[0158] The circulation mechanism 80 is controlled by the control
unit 33. The control unit 33 controls the circulation pump 82 of
the circulation mechanism 80 in such a manner that a circulation
flow rate Gc of return upstream is greater than a main stream flow
rate Gw of feeding to the water heat exchanger 21. The main stream
flow rate Gw is the flow rate of water flowing through the
downstream main pathway 27B. In a case where the first end 81a of
the circulation path 81 is connected to the downstream main pathway
27B, the main stream flow rate Gw is the flow rate of water flowing
through the downstream main pathway 27B, downstream of the
connection site of the first end 81a. The circulation flow rate Gc
is the flow rate of water flowing through the circulation path 81.
In a case where the circulation path 81 is branched, as in the
below-described Variation 7 illustrated in FIG. 23D, the
circulation flow rate Gc is the flow rate of water flowing through
the circulation path 81 before branching (upstream circulation path
810 illustrated in FIG. 23D).
[0159] The control unit 33 controls the circulation pump 82 to
adjust thereby the circulation flow rate Gc so as to lie within a
predetermined range. The scaling factor of the circulation flow
rate Gc with respect to the main stream flow rate Gw is not
particularly limited. In terms of enhancing the efficiency of
agitation of water flowing through the water flow channel (the
meandering flow channel in the present embodiment) inside the
container 47, the circulation flow rate Gc is preferably five times
or more the main stream flow rate Gw, and more preferably 10 times
or more the main stream flow rate Gw. The underlying reason for
setting a larger circulation flow rate Gc will be explained
next.
[0160] When electrolysis is performed in the water flow channel
between electrodes, scale precipitates at cathode-side regions, and
the concentration of scale component of water on the cathode sides
drops accordingly. Therefore, the scale component concentration at
cathode-side regions is lower than the scale component
concentration at anode-side regions. In heat pump hot-water supply
apparatuses, the amount of water that is heated in the water heat
exchanger (amount of water fed to the water heat exchanger) and the
amount of water that undergoes electrolysis in the electrolysis
device are ordinarily identical. Accordingly, the velocity of water
flowing through the water flow channel between electrodes in
conventional electrolysis devices is low, and the water flowing
through the water flow channel exhibits laminar flow.
[0161] In a specific example, the flow rate of water flowing
through the container of the electrolysis device is a low flow
rate, for instance of about 1 L/min. The velocity of water flowing
through the water flow channel between electrodes is for instance
of about 10 mm/s, in which case the Reynolds number ranges from
about 100 to 200.
[0162] The scale component concentration at the above-described
cathode-side regions is therefore kept low, regardless of the
presence of water of comparatively high scale component
concentration at anode-side regions. As a result, precipitation of
scale is slowed down, and the removal efficiency of scale component
(electrolysis efficiency) decreases.
[0163] In the present embodiment, therefore, the flow velocity of
water flowing through the water flow channel between the electrodes
51, 52 is raised by increasing the circulation flow rate Gc to be
greater than the main stream flow rate Gw. As a result, water is
agitated in the water flow channel, and there decreases the
difference between the scale component concentration at
cathode-side regions and the scale component concentration at
anode-side regions. The scale component concentration at
cathode-side regions becomes as a result higher than that before
agitation, and removal efficiency of scale component is therefore
increased.
[0164] In the present embodiment, the scaling factor of the
circulation flow rate Gc with respect to the main stream flow rate
Gw is increased, to enable thereby the velocity of water flowing
the water flow channel between the electrodes 51, 52 to increase
6-fold or more, and further, to increase 11-fold or more, as given
in Table 1 of the below-described working examples. A performance
ratio increases through disturbing of the flow on account of
increased water velocity. Further, flow can be made into turbulent
flow by increasing the scaling factor of the circulation flow rate
Gc with respect to the main stream flow rate Gw.
[0165] Variations 1 to 13 of the electrolysis device 41 and the
circulation mechanism 80 will be explained next. In the variations
below, for instance the sites at which the circulation path 81 of
the circulation mechanism 80 are connected are different from those
of the embodiment illustrated in FIG. 21A. Other features, control
of the circulation flow rate and so on are identical to those of
the embodiment illustrated in FIG. 21A, and hence will not be
explained in detail again.
[0166] FIG. 22A is a cross-sectional diagram illustrating Variation
1 of the electrolysis device 41 and the circulation mechanism 80.
In Variation 1, the first end 81a is provided at a position that
allows water flowing through the water flow channel between the
electrodes 51, 52 to be sucked into the circulation path 81. The
second end 81b is provided at a position that allows water to be
supplied into the water flow channel between electrodes 51, 52 that
lie upstream of the water flow channel.
[0167] In Variation 1, specifically, the first end 81a is disposed
between given electrodes 51, 52 inside the container 47, and the
second end 81b is disposed between electrodes 51, 52 lying further
upstream, but the embodiment is not limited thereto. One or both of
the first end 81a and the second end 81b may be for instance
connected to a joint, not shown, that protrudes outward from a wall
section of the container 47, in which case one or both of the first
end 81a and the second end 81b may be positioned outside the
container 47.
[0168] In Variation 1, the flow velocity of water can be
selectively increased at the water flow channel (circulation
section) between the site at which the first end 81a is provided
and the site at which the second end 81b is provided, in the water
flow channel inside the container 47. In a case where, for
instance, the electrolysis efficiency at the downstream region of
the water flow channel is to be increased, the first end 81a and
the second end 81b are disposed in such a manner that the
circulation section is provided at a position displaced towards the
downstream side, rather than to the center of the water flow
channel (center of the entire length of the water flow
channel).
[0169] FIG. 22B is a cross-sectional diagram illustrating Variation
2 of the electrolysis device 41 and the circulation mechanism 80.
In Variation 2, the first end 81a is provided at a position that
allows flowing in the water flow channel between the electrodes 51,
52 to be sucked into the circulation path 81. By contrast, the
second end 81b is provided at a position that allows water to be
supplied to the space S2 between the electrode furthest upstream,
and the wall section opposing this electrode (first wall section
471 in Variation 2).
[0170] In Variation 2, specifically, the first end 81a is disposed
between given electrodes 51, 52 inside the container 47, but the
embodiment is not limited thereto. The first end 81a may be for
instance connected to a joint, not shown, that protrudes outward
from a wall section of the container 47, in which case the first
end 81a is positioned outside the container 47. The second end 81b
is connected to the wall section (third wall section 473 in
Variation 2) that delimits the space S2. In FIG. 22B, the second
end 81b is disposed inside the space S2, but is not limited
thereto. The second end 81b may be for instance connected to a
joint, not shown, that protrudes outward from a wall section of the
container 47, in which case the second end 81b is positioned
outside the container 47. The feature wherein the first end 81a and
the second end 81b may be arranged inside or outside the container
47 applies also to the below-described variations.
[0171] In Variation 2, the flow velocity of water can be
selectively increased at the water flow channel (upstream water
flow channel) between the site at which the first end 81a is
provided and the site at which the second end 81b is provided, in
the water flow channel inside the container 47.
[0172] FIG. 22C is a cross-sectional diagram illustrating Variation
3 of the electrolysis device 41 and the circulation mechanism 80.
In Variation 3, the first end 81a is provided at a position that
allows water flowing through the space S1 between the electrode
furthest downstream and the wall section opposing this electrode
(second wall section 472 in Variation 3) to be sucked into the
circulation path 81. Meanwhile, the second end 81b is provided at a
position that allows water to be supplied to the water flow channel
between the electrodes 51, 52.
[0173] In Variation 3, the flow velocity of water can be
selectively increased at the water flow channel (downstream flow
channel) between the site at which the first end 81a is provided
and the site at which the second end 81b is provided, in the water
flow channel inside the container 47.
[0174] FIG. 23A is a cross-sectional diagram illustrating Variation
4 of the electrolysis device 41 and the circulation mechanism 80.
In Variation 4, the first end 81a of the circulation path 81 is
connected to the downstream main pathway 27B, and the second end
81b is connected to the upstream main pathway 27A.
[0175] FIG. 23B is a cross-sectional diagram illustrating Variation
5 of the electrolysis device 41 and the circulation mechanism 80.
In Variation 5, the first end 81a of the circulation path 81 is
connected to the downstream main pathway 27B, and the second end
81b is connected to the container 47. Specifically, the second end
81b may be provided at a position that allows supplying water to
the space S2 between the electrode furthest upstream, and the wall
section opposing this electrode (first wall section 471 in
Variation 5), but the embodiment is not limited thereto. The second
end 81b is provided at a position that allows water to be supplied
to the water flow channel between the electrodes 51, 52.
[0176] FIG. 23C is a cross-sectional diagram illustrating Variation
6 of the electrolysis device 41 and the circulation mechanism 80.
In Variation 6, the first end 81a of the circulation path 81 is
connected to the container 47, and the second end 81b is connected
to the upstream main pathway 27A. Specifically, the first end 81a
is provided at a position that allows water flowing through the
space S1 between the electrode furthest downstream and the wall
section opposing this electrode (second wall section 472 in
Variation 6) to be sucked into the circulation path 81, but the
embodiment is not limited thereto. The first end 81a may be
provided at a position that allows water to be supplied to the
water flow channel between the electrodes 51, 52.
[0177] FIG. 23D is a cross-sectional diagram illustrating Variation
7 of the electrolysis device 41 and the circulation mechanism 80.
In Variation 7, the circulation path 81 has an upstream circulation
path 810 that includes the first end 81a, and a plurality of branch
paths 811 to 815 that branch from the upstream circulation path
810. The first end 81a is connected to the downstream main pathway
27B. The ends of the branch paths 811 to 815 are connected to the
container 47. An end 811a of the branch path 811 is positioned
furthest downstream, while an end 811a of the branch path 815 is
positioned furthest upstream. The first end 81a may be connected to
the container 47.
[0178] FIG. 24A is a cross-sectional diagram illustrating Variation
8 of the electrolysis device 41 and the circulation mechanism 80,
FIG. 24B is a cross-sectional diagram illustrating Variation 9 of
the electrolysis device 41 and the circulation mechanism 80, and
FIG. 24C is a cross-sectional diagram illustrating Variation 10 of
the electrolysis device 41 and the circulation mechanism 80.
[0179] In Variations 8, 9 and 10, a valve is provided at any one,
or both, of an inlet side and outlet side of the container 47 of
the electrolysis device 41. In Variation 8, specifically, a check
valve 91 is provided in the upstream main pathway 27A, and a check
valve 92 is provided in the downstream main pathway 27B. In
Variation 9, the check valve 91 is provided in the upstream main
pathway 27A alone, while in Variation 10, the check valve 92 is
provided in the downstream main pathway 27B alone. Check valves are
thus provided in Variations 8, 9 and 10, and hence it becomes
possible to prevent backflow in the upstream main pathway 27A and
the downstream main pathway 27B.
[0180] The first end 81a and the second end 81b in Variations 8, 9
and 10 are connected to the container 47 of the electrolysis device
41.
[0181] FIG. 25A is a cross-sectional diagram illustrating Variation
11 of the electrolysis device 41 and the circulation mechanism 80,
FIG. 25B is a cross-sectional diagram illustrating Variation 12 of
the electrolysis device 41 and the circulation mechanism 80, and
FIG. 25C is a cross-sectional diagram illustrating Variation 13 of
the electrolysis device 41 and the circulation mechanism 80.
[0182] In Variations 11, 12 and 13, valves are provided in the same
way as in Variations 8, 9 and 10, except that herein the first end
81a is connected to the downstream main pathway 27B and the second
end 81b is connected to the upstream main pathway 27A.
[0183] In Variation 11, specifically, the check valve 91 is
provided in the upstream main pathway 27A, and the check valve 92
is provided in the downstream main pathway 27B. The check valve 91
is provided upstream of the second end 81b, and the check valve 92
is provided downstream of the first end 81a. In Variation 12, the
check valve 91 is provided in the upstream main pathway 27A alone.
The check valve 91 is provided upstream of the second end 81b. In
Variation 13, the check valve 92 is provided in the downstream main
pathway 27B alone. The check valve 92 is provided downstream of the
first end 81a. Check valves are thus provided in Variations 11, 12
and 13, and hence it becomes possible to prevent backflow in the
upstream main pathway 27A and the downstream main pathway 27B.
[0184] FIG. 26A is a side-view diagram illustrating Variation 14 of
the electrolysis device 41, and FIG. 26B is a cross-sectional
diagram of the electrolysis device 41 of Variation 14
(cross-sectional diagram along line B-B in FIG. 26A). In Variation
14 illustrated in FIGS. 26A and 26B, the water flow channel inside
the container 47 is a meandering flow channel such as that
illustrated in FIGS. 21A and 21B, but the water flow channel is not
limited thereto, and need not be a meandering flow channel.
[0185] In Variation 14, at least either the plurality of recesses
65 or the plurality of projections 66 are provided in one or both
electrodes of the electrode pairs 49. The recesses 65 and the
projections 66 may be provided at just some of the electrode pairs
49, from among the plurality of electrode pairs 49. Variation 14
shown in FIG. 26B illustrates an instance where the plurality of
recesses 65 and the plurality of projections 66 are provided in the
electrodes.
[0186] In Variation 14, as illustrated in FIGS. 26A and 26B, the
plurality of recesses 65 and plurality of projections 66 in the
electrodes are formed through working of a metal sheet material
(for instance, a flat metal thin sheet), not shown, for instance by
pressing in such a manner that one face of a metal sheet material
is sunk, whereby the other face thereof bulges out, but the
variation is not limited thereto. The electrodes thus formed have
the plurality of recesses 65 formed on one face thereof, and the
plurality of projections 66 of on the other face. The recesses 65
and the projections 66 are formed at identical positions, but on
mutually reverse faces, of the electrode plates.
[0187] In the present embodiment, the shape of the recesses 65 may
be a semispherical shape that is recessed in the thickness
direction in the electrodes, and the shapes of the projections 66
may be semispherical shapes that protrude in the thickness
direction of the electrodes, but may be other shapes, for instance
columnar, or prismatic shapes.
[0188] In FIGS. 26A and 26B, both the recesses 65 and the
projections 66 are provided in one given electrode, but the
embodiment is not limited thereto, and it is possible for one type
from among the recesses 65 and the projections 66 to be provided in
one electrode.
[0189] In Variation 14, water that flows through the water flow
channel between adjacent electrodes 51, 52 is agitated by at least
one type from among the plurality of recesses 65 and the plurality
of projections 66. As a result, there decreases the difference
between the scale component concentration at cathode-side regions
and the scale component concentration at anode-side regions. The
scale component concentration at cathode-side regions becomes as a
result higher than that before agitation, and removal efficiency of
scale component is therefore increased.
[0190] FIG. 27A is a cross-sectional diagram illustrating Variation
15 of the electrolysis device 41. In Variation 15, the water flow
channel inside the container 47 of the electrolysis device 41 is
not a meandering flow channel, as in the embodiment illustrated in
FIGS. 21A and 21B. The water flow channel in Variation 15 is made
up of a plurality of flow channels that extends along the side
walls of the container 47 (wall sections 473, 474 in FIG. 27A). The
plurality of flow channels in FIG. 27A is substantially parallel to
the side walls of the container 47, but is not limited thereto, and
may be inclined with respect to the side walls. The plurality of
flow channels are each formed by adjacent electrodes 51, 52.
[0191] The circulation path 81 of the circulation mechanism 80 may
be connected to the container 47, as illustrated in FIG. 27A,
Alternatively, the first end 81a of the circulation path 81 may be
connected to the downstream main pathway 27B, and the second end
81b may be connected to the upstream main pathway 27A, as
illustrated in FIG. 27B.
[0192] In the third embodiment, the plurality of electrodes 51, 52
may be flat plates having no through-holes, recesses or
protrusions, but are not limited thereto. The agitation means in
the third embodiment may comprise not only the circulation
mechanism 80, but additionally, also the inflow section of the
second embodiment. That is, at least some of the electrodes 51, 52
in third embodiment may be electrodes having the features of the
second embodiment. Specifically, at least some of the electrodes in
the third embodiment may have, for instance, the communicating
sections C, the recesses 65, projections 66 and so forth
illustrated in FIGS. 12 to 18. In this case, in the electrolysis
device 41a synergistic effect is obtained that combines the
agitation effect elicited by the circulation mechanism 80 of the
third embodiment, and the agitation effect elicited by the inflow
section of the second embodiment.
[0193] The agitation means in the third embodiment may comprise not
only the circulation mechanism 80, but additionally also the
agitation unit 60 of the first embodiment. Specifically, the
electrolysis device 41 in the third embodiment may comprise for
instance an agitation unit 60 such as the one illustrated in FIGS.
4 to 11. In this case, in the electrolysis device 41a synergistic
effect is obtained that combines the agitation effect elicited by
the circulation mechanism 80 of the third embodiment, and the
agitation effect elicited by the agitation unit 60 of the first
embodiment.
[0194] Table 1 is a set of data that illustrates the enhancing
effect on electrolysis efficiency that is achieved by increasing
the scaling factor of the circulation flow rate Gc with respect to
the main stream flow rate Gw. In Table 1, electrolysis efficiency
values are compared in the form of performance ratios. The
performance ratio is a value denoting the multiple of electrolysis
efficiency in a working example with respect to electrolysis
efficiency in a comparative example, taking the electrolysis
efficiency in the comparative example as 1.
[0195] Electrolysis efficiency in Examples 1 to 4 was evaluated
under the conditions given in Table 1, using the heat pump
hot-water supply apparatus 11 provided with the electrolysis device
41 and the circulation mechanism 80 illustrated in FIGS. 21A and
21B. In Examples 3 and 4, electrolysis efficiency was evaluated
under conditions for both an instance where there was used the
electrolysis device 41 provided with the electrodes having the
communicating sections C illustrated in FIG. 12A, and an instance
where there was used the electrolysis device 41 having the columnar
agitation members 61 illustrated in FIGS. 4A and 4B. An
electrolysis device 41 provided with no communicating sections C in
the electrodes, and provided with no agitation members 61, was used
in Examples 1 and 2.
[0196] In the comparative example and the reference example,
electrolysis efficiency was evaluated under the conditions given in
Table 1, using a heat pump hot-water supply apparatus provided with
no circulation mechanism. In the reference example, electrolysis
efficiency was evaluated under conditions for both an instance
where there was used the electrolysis device 41 provided with the
electrodes having the communicating sections C illustrated in FIG.
12A, and an instance where there was used the electrolysis device
41 having the columnar agitation members 61 illustrated in FIGS. 4A
and 4B. The evaluation results are given in Table 1.
TABLE-US-00001 TABLE 1 Comparative Reference example example
Example 1 Example 2 Example 3 Example 4 Main stream 1.0 1.0 1.0 1.0
1.0 1.0 flow rate Gw (L/min) Circulation 0 0 5 10 10 20 flow rate
Gc (L/min) Flow 10 10 60 110 110 210 velocity between electrodes
(mm/s) Reynolds 160 160 1000 1800 1800 3500 number Agitation None
Water None None Water Water unit for passage passage passage
agitation of holes holes holes water flow or or or channel columnar
columnar columnar between agitation agitation agitation electrodes
members members members Performance 1.0 1.3 1.1 1.4 1.6 1.8
ratio
[0197] As Table 1 shows, the electrolysis efficiency in Examples 1
to 4, where the multiple of the circulation flow rate Gc with
respect to the main stream flow rate Gw is 5 or more, exhibits
increased electrolysis efficiency with respect to the comparative
example. In Examples 1 to 4, the flow velocity of water in the
water flow channel between the electrodes 51, 52 has a magnitude
that is 6 times or more that of the comparative example.
[0198] Electrolysis efficiency increases significantly in Examples
2 to 4, where the multiple of the circulation flow rate Gc with
respect to the main stream flow rate Gw is 10 or greater.
[0199] The electrolysis efficiency in Example 3, further provided
with an agitation unit for agitation in the water flow channel,
exhibits a yet more significant increase in electrolysis efficiency
as compared with Example 2. As described above, the communicating
sections C provided in the electrodes or the agitation members 61
provided in the water flow channel are used in Example 3 as the
agitation unit. Electrolysis efficiency increases significantly in
a case where either one of the communicating sections C and the
agitation members 61 is used. In Example 4, the Reynolds number is
3500, and the flow of water is turbulent. In Example 4,
electrolysis efficiency is further increased with respect to that
of Example 3.
[0200] The flow of water in the water flow channel is laminar in a
case where the circulation mechanism 80 is not provided, as in the
reference example (Reynolds number of 160). It is deemed that,
therefore, the amount of water that passes through the
communicating sections C is unlikely to be large, and, accordingly,
water passes through the vicinity of the agitation members 61 in a
state of not being sufficiently disturbed.
[0201] In Example 3, by contrast, the circulation mechanism 80
renders the circulation flow rate Gc larger than the main stream
flow rate Gw. It is deemed that that, therefore, the amount of
water that passes through the communicating sections C is greater
than that in the reference example, and that water passing through
the agitation members 61 is disturbed more significantly than in
the reference example.
[0202] In the third embodiment and variations thereof, as explained
above, electrolysis efficiency can be increased, while curtailing
increases in cost derived from the electrodes, in a
temperature-adjusting water-supplying apparatus 11 that is provided
with the electrolysis device 41.
[0203] While circulating by virtue of the circulation mechanism 80,
water is continuously agitated in the water flow channel inside the
container 47, and hence cathode-side water and anode-side water in
the water flow channel are sufficiently mixed with each other, even
if the main stream flow rate Gw is low. Treated water (water having
undergone an electrolysis treatment) of stable quality is obtained
as a result as water circulates by virtue of the circulation
mechanism 80.
[0204] In the above temperature-adjusting water-supplying apparatus
11, disturbing is significant, and the effect of enhancing
electrolysis efficiency is more increased, as in the
above-described working examples, in a case where the circulation
flow rate Gc is five times or more the main stream flow rate
Gw.
[0205] In the third embodiment and variations thereof, the
agitation effect of water inside the container 47 can be enhanced
to a greater degree in an instance where at least one from among
the first end 81a and the second end 81b is connected to the
container 47 than in an instance where the first end 81a is
connected to the downstream main pathway 27B and the second end 81b
is connected to the upstream main pathway 27A. That is because
water inside the container 47 is disturbed more readily, in the
vicinity of the first end 81a, by the inflow of water into the
circulation path 81 via the first end 81a, while water inside the
container 47 in the vicinity of the second end 81b is disturbed
more readily, in the vicinity of the second end 81b, by the inflow
of water into the container 47 via the second end 81b.
[0206] In the temperature-adjusting water-supplying apparatus 11,
electrolysis efficiency is significantly enhanced thanks to the
synergistic effect that combines the effect elicited by increasing
the circulation flow rate Gc and the effect of the communicating
sections C, as in the working examples described above, in a case
where the communicating sections C that penetrate through the
electrodes, in the thickness direction thereof, are provided in at
least one of the electrodes of the electrode pairs 49.
[0207] In the temperature-adjusting water-supplying apparatus 11,
electrolysis efficiency is significantly enhanced thanks to the
synergistic effect that combines the effect elicited by increasing
the circulation flow rate Gc and the effect of the recesses 65
and/or projections 66, in a case where at least one type from among
the plurality of recesses 65 and the plurality of projections 66 is
provided in at least one of the electrodes of the electrode pairs
49.
[0208] In the temperature-adjusting water-supplying apparatus 11,
moreover, electrolysis efficiency is significantly enhanced thanks
to the synergistic effect that combines the effect elicited by
increasing the circulation flow rate Gc, and the effect of the
agitation members 61, as in the working examples described above,
in a case where the agitation members 61 that agitate water flowing
through the water flow channel between the electrode pairs 49 is
provided in the water flow channel.
[0209] Other Variations
[0210] The present invention is not limited to the above
embodiments, and may accommodate various modifications and
improvements without departing from the spirit of the
invention.
[0211] In the embodiments, the direction of the meandering flow
channel that is formed inside the container 47 may be the vertical
direction or the horizontal direction. In a meandering flow channel
that meanders in the horizontal direction, a cross-section of the
electrolysis device 41 illustrated in FIG. 2, when cut in a
cross-section along a plane parallel to the horizontal direction,
adopts a shape such as the one of FIG. 3A, and a cross-section of
the electrolysis device 41 illustrated in FIG. 2, when cut along a
cross-section along a plane parallel to the vertical direction,
adopts a shape such as the one illustrated in FIG. 3B.
[0212] The embodiments have been explained based on examples of
instances where, in the flow channel of water in the heat pump
hot-water supply apparatus 11, the electrolysis device 41 is
provided in the water inlet pipe 27 that is positioned upstream of
the water heat exchanger 21, and downstream of the pump 31, but the
embodiments are not limited thereto. It suffices that the
electrolysis device 41 be provided upstream of the water heat
exchanger 21, in the flow channel of water. Specifically, the
electrolysis device 41 may be for instance provided in the water
inlet pipe 27 upstream of the pump 31, or may be provided in the
water supply pipe 37 through which water is supplied from the water
supply source to the tank 15.
[0213] The embodiments have been explained based on examples of
instances where the container 47 is of substantially rectangular
parallelepiped shape, but the embodiments are not limited thereto.
The container 47 may be of prismatic shape, other than a
rectangular parallelepiped, or may be of columnar shape.
[0214] The embodiments have been explained based on example of a
once-through water heater, but the embodiments are not limited
thereto. The present invention can also be used in a water heater
of a type such that part of the water (hot water) that is supplied
through the hot water supply pipe 35 is returned again to the tank
15.
[0215] In the first embodiment, an instance has been illustrated
wherein the plurality of communicating sections C is provided in
the electrode plate, but it suffices that at least one
communicating section C be provided in the electrode plate.
[0216] In the embodiments, an instance has been illustrated in
which the temperature-adjusting water-supplying apparatus is the
heat pump hot-water supply apparatus 11, but the embodiments are
not limited thereto. Applications of the temperature-adjusting
water-supplying apparatus may include a case where a scale
component must be removed, for example, a heat pump hot-water
heater, a combustion-type hot-water supply apparatus, an electric
water warmer, a cooling tower or the like.
[0217] In the heat pump hot-water heater, high-temperature water
stored in the tank 15 can be used for heating or the like, for
instance in the configuration diagram illustrated in FIG. 1.
[0218] The above combustion-type hot-water supply apparatus
comprises the electrolysis device 41, and a water heat exchanger
21A provided downstream of the electrolysis device 41, as
illustrated in FIGS. 28, 29. In the combustion-type hot-water
supply apparatus, water is heated, in the water heat exchanger 21A,
using thermal energy obtained through burning of, for instance, a
gas for fuel.
[0219] The electric water warmer is provided with the electrolysis
device 41, and the water heat exchanger 21A provided downstream of
the electrolysis device 41, as illustrated in FIGS. 28, 29. In the
electric water warmer, water is heated, in the water heat exchanger
21A, using electric energy.
[0220] The cooling tower comprises, for instance, with the
electrolysis device 41, and the water heat exchanger 21A provided
downstream of the electrolysis device 41, as illustrated in FIGS.
28, 29. In the cooling tower, water is heated, at the water heat
exchanger 21A, through exchange of heat with a conveyed fluid that
carries heat generated in another device.
[0221] In FIG. 29, the circulation path 81 of the circulation
mechanism 80 is connected to the container 47, but the circulation
path 81 is not limited thereto, and may be connected to various
connection sites as illustrated in the above variations.
Overview of the Embodiments
[0222] An overview of the embodiments described above follows
next.
[0223] (1) The electrolysis device according to the first to third
embodiments removes a scale component contained in water that is
fed to a water heat exchanger. The electrolysis device comprises a
container having a water inlet port and a water outlet port; a
plurality of electrodes provided inside the container; and
agitation means for agitating water that flows between adjacent
electrodes, between the water inlet port and the water outlet
port.
[0224] In this configuration, water flowing between the electrodes
is agitated by the agitation means. It becomes possible as a result
to suppress drifting of water of low scale component concentration
towards the vicinity of those electrodes that function as anodes,
and hence the precipitation reaction of the scale component between
the electrodes is accordingly promoted. Therefore, the removal
efficiency of scale component in the water can be enhanced even
without increasing the surface area of the electrodes by resorting
to a means such as increasing the number of electrodes or
increasing the size of the electrodes. Therefore, it becomes
possible to increase the removal efficiency of scale component
while curtailing increases in cost derived from electrode
materials.
[0225] (2) In the electrolysis device, the agitation means may
include a component that is separate from the electrodes, or may be
formed in the electrodes themselves. Specific examples of the
former case include, for instance, the first embodiment and the
third embodiment. Specific examples of the latter case include, for
instance, the second embodiment.
[0226] (3) In the former case, the component may include a
circulation mechanism that causes water inside the container, or
water flowed out through the water outlet port of the container, to
return upstream, such that a circulation flow rate of water
returning upstream is greater than a main stream flow rate of water
fed to the water heat exchanger.
[0227] In this configuration, electrolysis efficiency in the
electrolysis device can be enhanced while suppressing cost
increases derived from the electrodes. The reason for this is as
follows.
[0228] Upon electrolysis in the water flow channel in the electrode
pairs, scale precipitates at cathode-side regions, and hence the
concentration of scale component decreases. Therefore, the scale
component concentration at cathode-side regions is lower than the
scale component concentration at anode-side regions. As a result,
precipitation of scale is slowed down, and the removal efficiency
of scale component (electrolysis efficiency) decreases.
[0229] In the temperature-adjusting water-supplying apparatus such
as the heat pump hot-water supply apparatus, the amount of water
that is heated in a water heat exchanger (amount of water fed to
the water heat exchanger), and the amount of water that undergoes
an electrolysis treatment in the electrolysis device, are
ordinarily identical. Accordingly, the velocity of water flowing
through the water flow channel between electrodes in conventional
electrolysis devices is low, and the water flowing through the
water flow channel exhibits laminar flow. The scale component
concentration at the above-described cathode-side regions is
therefore kept low, regardless of the presence of water of
comparatively high scale component concentration at anode-side
regions. Achieving sufficient electrolysis efficiency is thus
difficult.
[0230] In the present configuration, therefore, the flow velocity
of water flowing through the water flow channel in the electrode
pairs is enhanced by making the circulation flow rate greater than
the main stream flow rate of water that is fed to the water heat
exchanger. Thereby, water is agitated in the water flow channel,
and there decreases the difference between the scale component
concentration at cathode-side regions and the scale component
concentration at anode-side regions. The scale component
concentration at cathode-side regions becomes as a result higher
than that before agitation, at the above circulation flow rate, and
removal efficiency of scale component is therefore increased.
[0231] (4) In the electrolysis device, preferably, the circulation
flow rate is five times or more the main stream flow rate. The
effect of increasing flow disturbing is significant, and the effect
of enhancing electrolysis efficiency is more increased, as in the
below-described working examples, in a case where the circulation
flow rate is five times or more the main stream flow rate, as in
the present configuration.
[0232] (5) The electrolysis device may further comprise an upstream
main pathway, connected to the water inlet port of the container,
for supplying water to the container; and a downstream main pathway
that is connected to the water outlet port of the container and
that feeds, to the water heat exchanger, water that flows out of
the water outlet port; wherein the circulation mechanism includes a
circulation path and a circulation pump that causes water to flow
through the circulation path; a first end of the circulation path
may be connected to the container or the downstream main pathway;
and a second end of the circulation path may be connected to a
position, in the container, upstream of a connection site of the
first end, or to the upstream main pathway.
[0233] The agitation effect on water inside the container is
enhanced to a greater degree in an instance where at least one from
among the first end and the second end of the connection structure
is connected to the container, than in an instance where the first
end is connected to the downstream main pathway and the second end
is connected to the upstream main pathway. That is because water
inside the container is disturbed more readily, in the vicinity of
the first end, by the inflow of water into the circulation path via
the first end, while water inside the container in the vicinity of
the second end is disturbed more readily, in the vicinity of the
second end, by the inflow of water into the container via the
second end.
[0234] (6) The component may include a plurality of agitation
members that are arrayed along a direction of water flow, between
the adjacent electrodes. In this configuration, the removal
efficiency of scale component can be enhanced by just resorting to
a simple structure, namely an array of a plurality of agitation
members along the direction of water flow.
[0235] (7) In the electrolysis device, preferably, each of the
agitation members is formed of an insulating material. In this
configuration, the agitation members are formed of an insulating
material, and hence the configuration is advantageous in terms of
not being prone to corrosion, even when undergoing a prolonged
electrolysis treatment in a state where the agitation members are
disposed between the adjacent electrodes.
[0236] (8) In the electrolysis device, each of the agitation
members may extend in a direction that intersects the direction of
water flow, in a state where gaps are formed between the electrodes
and each of the agitation members. In this configuration, the
agitation members extend, between the adjacent electrodes, in a
direction that intersects the direction of water flow. Therefore,
the water flowing between the electrodes can be agitated
effectively. Moreover, the agitation members are disposed in a
state where gaps are provided between the adjacent electrodes, and
hence water can be agitated with good efficiency. By providing a
gap between the agitation members and the electrodes, a pathway is
created wherein the flow of water that flows between the electrodes
is split at the agitation members, and the resulting flow paths
merge again after having passed the agitation members. Water can be
agitated as a result with good efficiency.
[0237] (9) In the electrolysis device, the component may include a
stirrer that has a stirring blade disposed inside the container,
and a motor that is connected to the stirring blade.
[0238] In this configuration, the water inside the container is
forcibly agitated by the stirring blades, and hence the effect of
enhancing the removal efficiency of scale component is
increased.
[0239] (10) Specific examples of the latter case include the
following forms. Specifically, the plurality of electrodes have a
first electrode plate, a second electrode plate and a third
electrode plate, each of which has a plate-shape, the first
electrode plate, the second electrode plate and the third electrode
plate are arrayed in this order, spaced apart from one another, in
a plate thickness direction; a gap between the first electrode
plate and the second electrode plate functions as a first flow
channel through which water flows; a gap between the second
electrode plate and the third electrode plate functions as a second
flow channel through which water flows; and the agitation means
includes an inflow section provided in the second electrode plate,
part of water flowing through the first flow channel flows into the
second flow channel via the inflow section.
[0240] In this configuration, part of water flowing through the
first flow channel flows into the second flow channel via the
inflow section, and hence the inflowing water is mixed with water
flowing through the second flow. The flow of water through which
the second flow channel is disturbed through mixing of water this
way. Accordingly, it becomes possible to effectively suppress
drifting of water of low scale component concentration towards the
vicinity of the electrode plate that functions as an anode, from
among the second electrode plate and third electrode plate that
make up the second flow channel. Therefore, the precipitation
reaction of the scale component between the second electrode plate
and the third electrode plate is accordingly promoted.
[0241] The flow of water flowing through the vicinity of the inflow
section in the first flow channel is disturbed when, as explained
in the above section, part of the water that flows through the
first flow channel flows out of the first flow channel via the
inflow section. As a result, it becomes possible to effectively
suppress drifting of water of low scale component concentration
towards the vicinity of the electrode plate that functions as an
anode, from among the first electrode plate and the second
electrode plate that form the first flow channel, and hence the
precipitation reaction of the scale component between the first
electrode plate and the second electrode plate is accordingly
promoted.
[0242] As described above, this configuration allows increasing the
removal efficiency of scale component in water, even without
increasing the surface area of the electrode plates by increasing
the number of electrode plates. Therefore, it becomes possible to
increase the removal efficiency of scale component while curtailing
increases in cost derived from electrode materials.
[0243] (11) In the electrolysis device, preferably, the inflow
section includes a plurality of through-holes provided in the
second electrode plate. In this configuration, part of water
flowing through the first flow channel flows into the second flow
channel via the plurality of through-holes, and hence the effect of
agitation of water flowing through the second flow channel can be
further enhanced.
[0244] (12) In the electrolysis device, the inflow section may
include a communicating section provided on an edge of the second
electrode plate.
[0245] In this configuration, water flows from the first flow
channel into the second flow channel via the communicating section
that is provided at the edge of the second electrode plate. Such
water inflow disturbs the flow of water at the turn-back section
that is adjacent to the edge of the second electrode plate, and the
flow of water from the turn-back section into the second flow
channel. Therefore, the water that flows from the turn-back section
into the second flow channel exhibits a smaller difference between
the scale component concentration at a region on the side of the
second electrode plate 52 and the scale component concentration at
a region on the side of the third electrode plate 53. As a result,
it becomes possible to further suppress drifting of water of low
scale component concentration towards the second electrode plate
and the third electrode plate in the second flow channel.
[0246] (13) In the electrolysis device, at least one electrode
plate from among the first electrode plate, the second electrode
plate and the third electrode plate, may have at least either a
plurality of projections that protrude towards an adjacent
electrode plate or a plurality of recesses that are recessed
towards a side opposite to an adjacent electrode plate.
[0247] In this configuration, the flow of water in the flow channel
between adjacent electrode plates is disturbed by at least one type
of the plurality of projections and the plurality of recesses. As a
result, it becomes possible to further suppress drifting of water
of low scale component concentration towards the vicinity of those
electrodes that function as anodes, from among the adjacent
electrode plates. Therefore, the precipitation reaction of scale
component between electrode plates is further promoted.
[0248] (14) In the electrolysis device, preferably, the plurality
of electrodes form a meandering flow channel through which water
flows while meandering inside the container.
[0249] In this configuration, water that has flowed into the
container through the water inlet port flows along a meandering
pathway, from the upstream side towards the downstream side, along
the electrodes. Therefore, the contact surface area between the
electrodes and the water increases, and the removal efficiency of
scale component can be further enhanced.
[0250] (15) A temperature-adjusting water-supplying apparatus of
the present invention comprises a water heat exchanger that heats
water; and the above electrolysis device; wherein the
temperature-adjusting water-supplying apparatus supplies water, the
temperature of which has been adjusted in the water heat exchanger.
In this configuration, the temperature-adjusting water-supplying
apparatus comprises an electrolysis device such as the above one,
and hence the electrolysis device allows suppressing precipitation
of scale in the water heat exchanger while curtailing increases in
cost derived from electrode materials. [0251] 11 heat pump
hot-water supply apparatus [0252] 21 water heat exchanger [0253] 41
electrolysis device [0254] 43 water inlet port [0255] 45 water
outlet port [0256] 47 container [0257] 49 electrode pair [0258] 51
electrode [0259] 52 electrode [0260] 60 agitation unit [0261] 80
circulation mechanism [0262] 81 circulation path [0263] 82
circulation pump [0264] C communicating section
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